Beispiel #1
0
static void do_lincs(rvec *x,rvec *xp,matrix box,t_pbc *pbc,
                     struct gmx_lincsdata *lincsd,real *invmass,
					 t_commrec *cr,
                     real wangle,int *warn,
                     real invdt,rvec *v,
                     gmx_bool bCalcVir,tensor rmdr)
{
    int     b,i,j,k,n,iter;
    real    tmp0,tmp1,tmp2,im1,im2,mvb,rlen,len,len2,dlen2,wfac,lam;  
    rvec    dx;
    int     ncons,*bla,*blnr,*blbnb;
    rvec    *r;
    real    *blc,*blmf,*bllen,*blcc,*rhs1,*rhs2,*sol,*lambda;
    int     *nlocat;
    
    ncons  = lincsd->nc;
    bla    = lincsd->bla;
    r      = lincsd->tmpv;
    blnr   = lincsd->blnr;
    blbnb  = lincsd->blbnb;
    blc    = lincsd->blc;
    blmf   = lincsd->blmf;
    bllen  = lincsd->bllen;
    blcc   = lincsd->tmpncc;
    rhs1   = lincsd->tmp1;
    rhs2   = lincsd->tmp2;
    sol    = lincsd->tmp3;
    lambda = lincsd->lambda;
    
    if (DOMAINDECOMP(cr) && cr->dd->constraints)
    {
        nlocat = dd_constraints_nlocalatoms(cr->dd);
    }
    else if (PARTDECOMP(cr))
    {
        nlocat = pd_constraints_nlocalatoms(cr->pd);
    }
    else
    {
        nlocat = NULL;
    }
    
    *warn = 0;

    if (pbc)
    {
        /* Compute normalized i-j vectors */
        for(b=0; b<ncons; b++)
        {
            pbc_dx_aiuc(pbc,x[bla[2*b]],x[bla[2*b+1]],dx);
            unitv(dx,r[b]);
        }  
        for(b=0; b<ncons; b++)
        {
            for(n=blnr[b]; n<blnr[b+1]; n++)
            {
                blcc[n] = blmf[n]*iprod(r[b],r[blbnb[n]]);
            }
            pbc_dx_aiuc(pbc,xp[bla[2*b]],xp[bla[2*b+1]],dx);
            mvb = blc[b]*(iprod(r[b],dx) - bllen[b]);
            rhs1[b] = mvb;
            sol[b]  = mvb;
        }
    }
    else
    {
        /* Compute normalized i-j vectors */
        for(b=0; b<ncons; b++)
        {
            i = bla[2*b];
            j = bla[2*b+1];
            tmp0 = x[i][0] - x[j][0];
            tmp1 = x[i][1] - x[j][1];
            tmp2 = x[i][2] - x[j][2];
            rlen = gmx_invsqrt(tmp0*tmp0+tmp1*tmp1+tmp2*tmp2);
            r[b][0] = rlen*tmp0;
            r[b][1] = rlen*tmp1;
            r[b][2] = rlen*tmp2;
        } /* 16 ncons flops */
        
        for(b=0; b<ncons; b++)
        {
            tmp0 = r[b][0];
            tmp1 = r[b][1];
            tmp2 = r[b][2];
            len = bllen[b];
            i = bla[2*b];
            j = bla[2*b+1];
            for(n=blnr[b]; n<blnr[b+1]; n++)
            {
                k = blbnb[n];
                blcc[n] = blmf[n]*(tmp0*r[k][0] + tmp1*r[k][1] + tmp2*r[k][2]); 
            } /* 6 nr flops */
            mvb = blc[b]*(tmp0*(xp[i][0] - xp[j][0]) +
                          tmp1*(xp[i][1] - xp[j][1]) +    
                          tmp2*(xp[i][2] - xp[j][2]) - len);
            rhs1[b] = mvb;
            sol[b]  = mvb;
            /* 10 flops */
        }
        /* Together: 26*ncons + 6*nrtot flops */
    }
    
    lincs_matrix_expand(lincsd,blcc,rhs1,rhs2,sol);
    /* nrec*(ncons+2*nrtot) flops */
    
    for(b=0; b<ncons; b++)
    {
        i = bla[2*b];
        j = bla[2*b+1];
        mvb = blc[b]*sol[b];
        lambda[b] = -mvb;
        im1 = invmass[i];
        im2 = invmass[j];
        tmp0 = r[b][0]*mvb;
        tmp1 = r[b][1]*mvb;
        tmp2 = r[b][2]*mvb;
        xp[i][0] -= tmp0*im1;
        xp[i][1] -= tmp1*im1;
        xp[i][2] -= tmp2*im1;
        xp[j][0] += tmp0*im2;
        xp[j][1] += tmp1*im2;
        xp[j][2] += tmp2*im2;
    } /* 16 ncons flops */


    /*     
     ********  Correction for centripetal effects  ********  
     */
  
    wfac = cos(DEG2RAD*wangle);
    wfac = wfac*wfac;
	
    for(iter=0; iter<lincsd->nIter; iter++)
    {
        if (DOMAINDECOMP(cr) && cr->dd->constraints)
        {
            /* Communicate the corrected non-local coordinates */
            dd_move_x_constraints(cr->dd,box,xp,NULL);
        } 
		else if (PARTDECOMP(cr))
		{
			pd_move_x_constraints(cr,xp,NULL);
		}	
        
        for(b=0; b<ncons; b++)
        {
            len = bllen[b];
            if (pbc)
            {
                pbc_dx_aiuc(pbc,xp[bla[2*b]],xp[bla[2*b+1]],dx);
            }
            else
            {
                rvec_sub(xp[bla[2*b]],xp[bla[2*b+1]],dx);
            }
            len2 = len*len;
            dlen2 = 2*len2 - norm2(dx);
            if (dlen2 < wfac*len2 && (nlocat==NULL || nlocat[b]))
            {
                *warn = b;
            }
            if (dlen2 > 0)
            {
                mvb = blc[b]*(len - dlen2*gmx_invsqrt(dlen2));
            }
            else
            {
                mvb = blc[b]*len;
            }
            rhs1[b] = mvb;
            sol[b]  = mvb;
        } /* 20*ncons flops */
        
        lincs_matrix_expand(lincsd,blcc,rhs1,rhs2,sol);
        /* nrec*(ncons+2*nrtot) flops */
        
        for(b=0; b<ncons; b++)
        {
            i = bla[2*b];
            j = bla[2*b+1];
            lam = lambda[b];
            mvb = blc[b]*sol[b];
            lambda[b] = lam - mvb;
            im1 = invmass[i];
            im2 = invmass[j];
            tmp0 = r[b][0]*mvb;
            tmp1 = r[b][1]*mvb;
            tmp2 = r[b][2]*mvb;
            xp[i][0] -= tmp0*im1;
            xp[i][1] -= tmp1*im1;
            xp[i][2] -= tmp2*im1;
            xp[j][0] += tmp0*im2;
            xp[j][1] += tmp1*im2;
            xp[j][2] += tmp2*im2;
        } /* 17 ncons flops */
    } /* nit*ncons*(37+9*nrec) flops */
    
    if (v)
    {
        /* Correct the velocities */
        for(b=0; b<ncons; b++)
        {
            i = bla[2*b];
            j = bla[2*b+1];
            im1 = invmass[i]*lambda[b]*invdt;
            im2 = invmass[j]*lambda[b]*invdt;
            v[i][0] += im1*r[b][0];
            v[i][1] += im1*r[b][1];
            v[i][2] += im1*r[b][2];
            v[j][0] -= im2*r[b][0];
            v[j][1] -= im2*r[b][1];
            v[j][2] -= im2*r[b][2];
        } /* 16 ncons flops */
    }
    
    if (nlocat)
    {
        /* Only account for local atoms */
        for(b=0; b<ncons; b++)
        {
            lambda[b] *= 0.5*nlocat[b];
        }
    }
    
    if (bCalcVir)
    {
        /* Constraint virial */
        for(b=0; b<ncons; b++)
        {
            tmp0 = bllen[b]*lambda[b];
            for(i=0; i<DIM; i++)
            {
                tmp1 = tmp0*r[b][i];
                for(j=0; j<DIM; j++)
                {
                    rmdr[i][j] -= tmp1*r[b][j];
                }
            }
        } /* 22 ncons flops */
    }
    
    /* Total:
     * 26*ncons + 6*nrtot + nrec*(ncons+2*nrtot)
     * + nit * (20*ncons + nrec*(ncons+2*nrtot) + 17 ncons)
     *
     * (26+nrec)*ncons + (6+2*nrec)*nrtot
     * + nit * ((37+nrec)*ncons + 2*nrec*nrtot)
     * if nit=1
     * (63+nrec)*ncons + (6+4*nrec)*nrtot
     */
}
Beispiel #2
0
gmx_bool constrain(FILE *fplog, gmx_bool bLog, gmx_bool bEner,
                   struct gmx_constr *constr,
                   t_idef *idef, t_inputrec *ir, gmx_ekindata_t *ekind,
                   t_commrec *cr,
                   gmx_int64_t step, int delta_step,
                   t_mdatoms *md,
                   rvec *x, rvec *xprime, rvec *min_proj,
                   gmx_bool bMolPBC, matrix box,
                   real lambda, real *dvdlambda,
                   rvec *v, tensor *vir,
                   t_nrnb *nrnb, int econq, gmx_bool bPscal,
                   real veta, real vetanew)
{
    gmx_bool    bOK, bDump;
    int         start, homenr, nrend;
    int         i, j, d;
    int         ncons, settle_error;
    tensor      vir_r_m_dr;
    rvec       *vstor;
    real        invdt, vir_fac, t;
    t_ilist    *settle;
    int         nsettle;
    t_pbc       pbc, *pbc_null;
    char        buf[22];
    t_vetavars  vetavar;
    int         nth, th;

    if (econq == econqForceDispl && !EI_ENERGY_MINIMIZATION(ir->eI))
    {
        gmx_incons("constrain called for forces displacements while not doing energy minimization, can not do this while the LINCS and SETTLE constraint connection matrices are mass weighted");
    }

    bOK   = TRUE;
    bDump = FALSE;

    start  = 0;
    homenr = md->homenr;
    nrend  = start+homenr;

    /* set constants for pressure control integration */
    init_vetavars(&vetavar, econq != econqCoord,
                  veta, vetanew, ir, ekind, bPscal);

    if (ir->delta_t == 0)
    {
        invdt = 0;
    }
    else
    {
        invdt  = 1/ir->delta_t;
    }

    if (ir->efep != efepNO && EI_DYNAMICS(ir->eI))
    {
        /* Set the constraint lengths for the step at which this configuration
         * is meant to be. The invmasses should not be changed.
         */
        lambda += delta_step*ir->fepvals->delta_lambda;
    }

    if (vir != NULL)
    {
        clear_mat(vir_r_m_dr);
    }

    where();

    settle  = &idef->il[F_SETTLE];
    nsettle = settle->nr/(1+NRAL(F_SETTLE));

    if (nsettle > 0)
    {
        nth = gmx_omp_nthreads_get(emntSETTLE);
    }
    else
    {
        nth = 1;
    }

    if (nth > 1 && constr->vir_r_m_dr_th == NULL)
    {
        snew(constr->vir_r_m_dr_th, nth);
        snew(constr->settle_error, nth);
    }

    settle_error = -1;

    /* We do not need full pbc when constraints do not cross charge groups,
     * i.e. when dd->constraint_comm==NULL.
     * Note that PBC for constraints is different from PBC for bondeds.
     * For constraints there is both forward and backward communication.
     */
    if (ir->ePBC != epbcNONE &&
        (cr->dd || bMolPBC) && !(cr->dd && cr->dd->constraint_comm == NULL))
    {
        /* With pbc=screw the screw has been changed to a shift
         * by the constraint coordinate communication routine,
         * so that here we can use normal pbc.
         */
        pbc_null = set_pbc_dd(&pbc, ir->ePBC, cr->dd, FALSE, box);
    }
    else
    {
        pbc_null = NULL;
    }

    /* Communicate the coordinates required for the non-local constraints
     * for LINCS and/or SETTLE.
     */
    if (cr->dd)
    {
        dd_move_x_constraints(cr->dd, box, x, xprime, econq == econqCoord);
    }

    if (constr->lincsd != NULL)
    {
        bOK = constrain_lincs(fplog, bLog, bEner, ir, step, constr->lincsd, md, cr,
                              x, xprime, min_proj,
                              box, pbc_null, lambda, dvdlambda,
                              invdt, v, vir != NULL, vir_r_m_dr,
                              econq, nrnb,
                              constr->maxwarn, &constr->warncount_lincs);
        if (!bOK && constr->maxwarn >= 0)
        {
            if (fplog != NULL)
            {
                fprintf(fplog, "Constraint error in algorithm %s at step %s\n",
                        econstr_names[econtLINCS], gmx_step_str(step, buf));
            }
            bDump = TRUE;
        }
    }

    if (constr->nblocks > 0)
    {
        switch (econq)
        {
            case (econqCoord):
                bOK = bshakef(fplog, constr->shaked,
                              md->invmass, constr->nblocks, constr->sblock,
                              idef, ir, x, xprime, nrnb,
                              constr->lagr, lambda, dvdlambda,
                              invdt, v, vir != NULL, vir_r_m_dr,
                              constr->maxwarn >= 0, econq, &vetavar);
                break;
            case (econqVeloc):
                bOK = bshakef(fplog, constr->shaked,
                              md->invmass, constr->nblocks, constr->sblock,
                              idef, ir, x, min_proj, nrnb,
                              constr->lagr, lambda, dvdlambda,
                              invdt, NULL, vir != NULL, vir_r_m_dr,
                              constr->maxwarn >= 0, econq, &vetavar);
                break;
            default:
                gmx_fatal(FARGS, "Internal error, SHAKE called for constraining something else than coordinates");
                break;
        }

        if (!bOK && constr->maxwarn >= 0)
        {
            if (fplog != NULL)
            {
                fprintf(fplog, "Constraint error in algorithm %s at step %s\n",
                        econstr_names[econtSHAKE], gmx_step_str(step, buf));
            }
            bDump = TRUE;
        }
    }

    if (nsettle > 0)
    {
        int calcvir_atom_end;

        if (vir == NULL)
        {
            calcvir_atom_end = 0;
        }
        else
        {
            calcvir_atom_end = md->homenr;
        }

        switch (econq)
        {
            case econqCoord:
#pragma omp parallel for num_threads(nth) schedule(static)
                for (th = 0; th < nth; th++)
                {
                    int start_th, end_th;

                    if (th > 0)
                    {
                        clear_mat(constr->vir_r_m_dr_th[th]);
                    }

                    start_th = (nsettle* th   )/nth;
                    end_th   = (nsettle*(th+1))/nth;
                    if (start_th >= 0 && end_th - start_th > 0)
                    {
                        csettle(constr->settled,
                                end_th-start_th,
                                settle->iatoms+start_th*(1+NRAL(F_SETTLE)),
                                pbc_null,
                                x[0], xprime[0],
                                invdt, v ? v[0] : NULL, calcvir_atom_end,
                                th == 0 ? vir_r_m_dr : constr->vir_r_m_dr_th[th],
                                th == 0 ? &settle_error : &constr->settle_error[th],
                                &vetavar);
                    }
                }
                inc_nrnb(nrnb, eNR_SETTLE, nsettle);
                if (v != NULL)
                {
                    inc_nrnb(nrnb, eNR_CONSTR_V, nsettle*3);
                }
                if (vir != NULL)
                {
                    inc_nrnb(nrnb, eNR_CONSTR_VIR, nsettle*3);
                }
                break;
            case econqVeloc:
            case econqDeriv:
            case econqForce:
            case econqForceDispl:
#pragma omp parallel for num_threads(nth) schedule(static)
                for (th = 0; th < nth; th++)
                {
                    int start_th, end_th;

                    if (th > 0)
                    {
                        clear_mat(constr->vir_r_m_dr_th[th]);
                    }

                    start_th = (nsettle* th   )/nth;
                    end_th   = (nsettle*(th+1))/nth;

                    if (start_th >= 0 && end_th - start_th > 0)
                    {
                        settle_proj(constr->settled, econq,
                                    end_th-start_th,
                                    settle->iatoms+start_th*(1+NRAL(F_SETTLE)),
                                    pbc_null,
                                    x,
                                    xprime, min_proj, calcvir_atom_end,
                                    th == 0 ? vir_r_m_dr : constr->vir_r_m_dr_th[th],
                                    &vetavar);
                    }
                }
                /* This is an overestimate */
                inc_nrnb(nrnb, eNR_SETTLE, nsettle);
                break;
            case econqDeriv_FlexCon:
                /* Nothing to do, since the are no flexible constraints in settles */
                break;
            default:
                gmx_incons("Unknown constraint quantity for settle");
        }
    }

    if (settle->nr > 0)
    {
        /* Combine virial and error info of the other threads */
        for (i = 1; i < nth; i++)
        {
            m_add(vir_r_m_dr, constr->vir_r_m_dr_th[i], vir_r_m_dr);
            settle_error = constr->settle_error[i];
        }

        if (econq == econqCoord && settle_error >= 0)
        {
            bOK = FALSE;
            if (constr->maxwarn >= 0)
            {
                char buf[256];
                sprintf(buf,
                        "\nstep " "%"GMX_PRId64 ": Water molecule starting at atom %d can not be "
                        "settled.\nCheck for bad contacts and/or reduce the timestep if appropriate.\n",
                        step, ddglatnr(cr->dd, settle->iatoms[settle_error*(1+NRAL(F_SETTLE))+1]));
                if (fplog)
                {
                    fprintf(fplog, "%s", buf);
                }
                fprintf(stderr, "%s", buf);
                constr->warncount_settle++;
                if (constr->warncount_settle > constr->maxwarn)
                {
                    too_many_constraint_warnings(-1, constr->warncount_settle);
                }
                bDump = TRUE;
            }
        }
    }

    free_vetavars(&vetavar);

    if (vir != NULL)
    {
        switch (econq)
        {
            case econqCoord:
                vir_fac = 0.5/(ir->delta_t*ir->delta_t);
                break;
            case econqVeloc:
                vir_fac = 0.5/ir->delta_t;
                break;
            case econqForce:
            case econqForceDispl:
                vir_fac = 0.5;
                break;
            default:
                vir_fac = 0;
                gmx_incons("Unsupported constraint quantity for virial");
        }

        if (EI_VV(ir->eI))
        {
            vir_fac *= 2;  /* only constraining over half the distance here */
        }
        for (i = 0; i < DIM; i++)
        {
            for (j = 0; j < DIM; j++)
            {
                (*vir)[i][j] = vir_fac*vir_r_m_dr[i][j];
            }
        }
    }

    if (bDump)
    {
        dump_confs(fplog, step, constr->warn_mtop, start, homenr, cr, x, xprime, box);
    }

    if (econq == econqCoord)
    {
        if (ir->ePull == epullCONSTRAINT)
        {
            if (EI_DYNAMICS(ir->eI))
            {
                t = ir->init_t + (step + delta_step)*ir->delta_t;
            }
            else
            {
                t = ir->init_t;
            }
            set_pbc(&pbc, ir->ePBC, box);
            pull_constraint(ir->pull, md, &pbc, cr, ir->delta_t, t, x, xprime, v, *vir);
        }
        if (constr->ed && delta_step > 0)
        {
            /* apply the essential dynamcs constraints here */
            do_edsam(ir, step, cr, xprime, v, box, constr->ed);
        }
    }

    return bOK;
}
Beispiel #3
0
gmx_bool constrain_lincs(FILE *fplog,gmx_bool bLog,gmx_bool bEner,
                     t_inputrec *ir,
                     gmx_large_int_t step,
                     struct gmx_lincsdata *lincsd,t_mdatoms *md,
                     t_commrec *cr, 
                     rvec *x,rvec *xprime,rvec *min_proj,matrix box,
                     real lambda,real *dvdlambda,
                     real invdt,rvec *v,
                     gmx_bool bCalcVir,tensor rmdr,
                     int econq,
                     t_nrnb *nrnb,
                     int maxwarn,int *warncount)
{
    char  buf[STRLEN],buf2[22],buf3[STRLEN];
    int   i,warn,p_imax,error;
    real  ncons_loc,p_ssd,p_max;
    t_pbc pbc,*pbc_null;
    rvec  dx;
    gmx_bool  bOK;
    
    bOK = TRUE;
    
    if (lincsd->nc == 0 && cr->dd == NULL)
    {
        if (bLog || bEner)
        {
            lincsd->rmsd_data[0] = 0;
            if (ir->eI == eiSD2 && v == NULL)
            {
                i = 2;
            }
            else
            {
                i = 1;
            }
            lincsd->rmsd_data[i] = 0;
        }
        
        return bOK;
    }
    
    /* We do not need full pbc when constraints do not cross charge groups,
     * i.e. when dd->constraint_comm==NULL
     */
    if ((cr->dd || ir->bPeriodicMols) && !(cr->dd && cr->dd->constraint_comm==NULL))
    {
        /* With pbc=screw the screw has been changed to a shift
         * by the constraint coordinate communication routine,
         * so that here we can use normal pbc.
         */
        pbc_null = set_pbc_dd(&pbc,ir->ePBC,cr->dd,FALSE,box);
    }
    else
    {
        pbc_null = NULL;
    }
    if (cr->dd)
    {
        /* Communicate the coordinates required for the non-local constraints */
        dd_move_x_constraints(cr->dd,box,x,xprime);
        /* dump_conf(dd,lincsd,NULL,"con",TRUE,xprime,box); */
    }
	else if (PARTDECOMP(cr))
	{
		pd_move_x_constraints(cr,x,xprime);
	}	
	
    if (econq == econqCoord)
    {
        if (ir->efep != efepNO)
        {
            if (md->nMassPerturbed && lincsd->matlam != md->lambda)
            {
                set_lincs_matrix(lincsd,md->invmass,md->lambda);
            }
            
            for(i=0; i<lincsd->nc; i++)
            {
                lincsd->bllen[i] = lincsd->bllen0[i] + lambda*lincsd->ddist[i];
            }
        }
        
        if (lincsd->ncg_flex)
        {
            /* Set the flexible constraint lengths to the old lengths */
            if (pbc_null)
            {
                for(i=0; i<lincsd->nc; i++)
                {
                    if (lincsd->bllen[i] == 0) {
                        pbc_dx_aiuc(pbc_null,x[lincsd->bla[2*i]],x[lincsd->bla[2*i+1]],dx);
                        lincsd->bllen[i] = norm(dx);
                    }
                }
            }
            else
            {
                for(i=0; i<lincsd->nc; i++)
                {
                    if (lincsd->bllen[i] == 0)
                    {
                        lincsd->bllen[i] =
                            sqrt(distance2(x[lincsd->bla[2*i]],
                                           x[lincsd->bla[2*i+1]]));
                    }
                }
            }
        }
        
        if (bLog && fplog)
        {
            cconerr(cr->dd,lincsd->nc,lincsd->bla,lincsd->bllen,xprime,pbc_null,
                    &ncons_loc,&p_ssd,&p_max,&p_imax);
        }
        
        do_lincs(x,xprime,box,pbc_null,lincsd,md->invmass,cr,
                 ir->LincsWarnAngle,&warn,
                 invdt,v,bCalcVir,rmdr);
        
        if (ir->efep != efepNO)
        {
            real dt_2,dvdl=0;
            
            dt_2 = 1.0/(ir->delta_t*ir->delta_t);
            for(i=0; (i<lincsd->nc); i++)
            {
                dvdl += lincsd->lambda[i]*dt_2*lincsd->ddist[i];
            }
            *dvdlambda += dvdl;
		}
        
        if (bLog && fplog && lincsd->nc > 0)
        {
            fprintf(fplog,"   Rel. Constraint Deviation:  RMS         MAX     between atoms\n");
            fprintf(fplog,"       Before LINCS          %.6f    %.6f %6d %6d\n",
                    sqrt(p_ssd/ncons_loc),p_max,
                    ddglatnr(cr->dd,lincsd->bla[2*p_imax]),
                    ddglatnr(cr->dd,lincsd->bla[2*p_imax+1]));
        }
        if (bLog || bEner)
        {
            cconerr(cr->dd,lincsd->nc,lincsd->bla,lincsd->bllen,xprime,pbc_null,
                    &ncons_loc,&p_ssd,&p_max,&p_imax);
            /* Check if we are doing the second part of SD */
            if (ir->eI == eiSD2 && v == NULL)
            {
                i = 2;
            }
            else
            {
                i = 1;
            }
            lincsd->rmsd_data[0] = ncons_loc;
            lincsd->rmsd_data[i] = p_ssd;
        }
        else
        {
            lincsd->rmsd_data[0] = 0;
            lincsd->rmsd_data[1] = 0;
            lincsd->rmsd_data[2] = 0;
        }
        if (bLog && fplog && lincsd->nc > 0)
        {
            fprintf(fplog,
                    "        After LINCS          %.6f    %.6f %6d %6d\n\n",
                    sqrt(p_ssd/ncons_loc),p_max,
                    ddglatnr(cr->dd,lincsd->bla[2*p_imax]),
                    ddglatnr(cr->dd,lincsd->bla[2*p_imax+1]));
        }
        
        if (warn > 0)
        {
            if (maxwarn >= 0)
            {
                cconerr(cr->dd,lincsd->nc,lincsd->bla,lincsd->bllen,xprime,pbc_null,
                        &ncons_loc,&p_ssd,&p_max,&p_imax);
                if (MULTISIM(cr))
                {
                    sprintf(buf3," in simulation %d", cr->ms->sim);
                }
                else
                {
                    buf3[0] = 0;
                }
                sprintf(buf,"\nStep %s, time %g (ps)  LINCS WARNING%s\n"
                        "relative constraint deviation after LINCS:\n"
                        "rms %.6f, max %.6f (between atoms %d and %d)\n",
                        gmx_step_str(step,buf2),ir->init_t+step*ir->delta_t,
                        buf3,
                        sqrt(p_ssd/ncons_loc),p_max,
                        ddglatnr(cr->dd,lincsd->bla[2*p_imax]),
                        ddglatnr(cr->dd,lincsd->bla[2*p_imax+1]));
                if (fplog)
                {
                    fprintf(fplog,"%s",buf);
                }
                fprintf(stderr,"%s",buf);
                lincs_warning(fplog,cr->dd,x,xprime,pbc_null,
                              lincsd->nc,lincsd->bla,lincsd->bllen,
                              ir->LincsWarnAngle,maxwarn,warncount);
            }
            bOK = (p_max < 0.5);
        }
        
        if (lincsd->ncg_flex) {
            for(i=0; (i<lincsd->nc); i++)
                if (lincsd->bllen0[i] == 0 && lincsd->ddist[i] == 0)
                    lincsd->bllen[i] = 0;
        }
    } 
    else
    {
        do_lincsp(x,xprime,min_proj,pbc_null,lincsd,md->invmass,econq,dvdlambda,
                  bCalcVir,rmdr);
    }
  
    /* count assuming nit=1 */
    inc_nrnb(nrnb,eNR_LINCS,lincsd->nc);
    inc_nrnb(nrnb,eNR_LINCSMAT,(2+lincsd->nOrder)*lincsd->ncc);
    if (lincsd->ntriangle > 0)
    {
        inc_nrnb(nrnb,eNR_LINCSMAT,lincsd->nOrder*lincsd->ncc_triangle);
    }
    if (v)
    {
        inc_nrnb(nrnb,eNR_CONSTR_V,lincsd->nc*2);
    }
    if (bCalcVir)
    {
        inc_nrnb(nrnb,eNR_CONSTR_VIR,lincsd->nc);
    }

    return bOK;
}