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half-bond lists and no bond migration for local hyper

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This commit is contained in:
Steve Plimpton
2019-02-26 16:17:31 -07:00
parent 12bec9cbad
commit eea30c5b76
4 changed files with 814 additions and 755 deletions
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124
src/REPLICA/fix_hyper_global.cpp
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@ -32,12 +32,12 @@
using namespace LAMMPS_NS;
using namespace FixConst;
#define DELTA 16384
#define DELTABOND 16384
#define VECLEN 5
// NOTE: count/output # of timesteps on which bias is non-zero
// NOTE: should there be a virial contribution from boosted bond?
// NOTE: allow newton off? see Note in pre_reverse()
// possible enhancements
// should there be a virial contribution from boosted bond?
// allow newton off? see Note in pre_reverse()
/* ---------------------------------------------------------------------- */
@ -102,7 +102,6 @@ int FixHyperGlobal::setmask()
{
int mask = 0;
mask |= PRE_NEIGHBOR;
mask |= PRE_FORCE;
mask |= PRE_REVERSE;
mask |= THERMO_ENERGY;
return mask;
@ -124,6 +123,10 @@ void FixHyperGlobal::init()
if (force->newton_pair == 0)
error->all(FLERR,"Hyper global requires newton pair on");
if (atom->molecular && me == 0)
error->warning(FLERR,"Hyper global for molecular systems "
"requires care in defining hyperdynamic bonds");
dt = update->dt;
// need an occasional half neighbor list
@ -167,15 +170,56 @@ void FixHyperGlobal::setup_pre_reverse(int eflag, int vflag)
void FixHyperGlobal::pre_neighbor()
{
int m,iold,jold,ilocal,jlocal;
int i,m,iold,jold,ilocal,jlocal;
double distsq;
// reset local IDs for owned bond atoms, since atoms have migrated
// uses xold and tagold from when bonds were created
// reset local indices for owned bond atoms, since atoms have migrated
// must be done after ghost atoms are setup via comm->borders()
// first time this is done for a particular I or J atom:
// use tagold and xold from when bonds were created
// atom->map() finds atom ID if it exists, owned index if possible
// closest current I or J atoms to old I may now be ghost atoms
// closest_image() returns the ghost atom index in that case
// also compute max drift of any atom in a bond
// drift = displacement from quenched coord while event has not yet occured
for (i = 0; i < nall_old; i++) old2now[i] = -1;
double **x = atom->x;
for (m = 0; m < nblocal; m++) {
iold = blist[m].iold;
jold = blist[m].jold;
ilocal = old2now[iold];
jlocal = old2now[jold];
if (ilocal < 0) {
ilocal = atom->map(tagold[iold]);
ilocal = domain->closest_image(xold[iold],ilocal);
if (ilocal < 0)
error->one(FLERR,"Fix hyper/global bond atom not found");
old2now[iold] = ilocal;
distsq = MathExtra::distsq3(x[ilocal],xold[iold]);
maxdriftsq = MAX(distsq,maxdriftsq);
}
if (jlocal < 0) {
jlocal = atom->map(tagold[jold]);
jlocal = domain->closest_image(xold[iold],jlocal); // closest to iold
if (jlocal < 0)
error->one(FLERR,"Fix hyper/global bond atom not found");
old2now[jold] = jlocal;
distsq = MathExtra::distsq3(x[jlocal],xold[jold]);
maxdriftsq = MAX(distsq,maxdriftsq);
}
blist[m].i = ilocal;
blist[m].j = jlocal;
}
/* old way - nblocal loop is re-doing index-find calculation
// NOTE: drift may not include J atoms moving (if not themselves bond owners)
int flag = 0;
for (m = 0; m < nblocal; m++) {
@ -196,6 +240,8 @@ void FixHyperGlobal::pre_neighbor()
}
if (flag) error->one(FLERR,"Fix hyper/global bond atom not found");
*/
}
/* ---------------------------------------------------------------------- */
@ -204,15 +250,16 @@ void FixHyperGlobal::pre_reverse(int /* eflag */, int /* vflag */)
{
int i,j,m,imax,jmax;
double delx,dely,delz;
double r,r0,estrain,rmax,r0max,emax,dt_boost;
double vbias,fbias,fbiasr;
double r,r0,estrain,rmax,r0max,dt_boost;
double ebias,vbias,fbias,fbiasr;
// compute current strain of each owned bond
// emax = maximum strain of any bond I own
// eabs_max = maximum absolute value of strain of any bond I own
// imax,jmax = local indices of my 2 atoms in that bond
// rmax,r0max = current and relaxed lengths of that bond
double **x = atom->x;
emax = 0.0;
double estrain_maxabs = 0.0;
for (m = 0; m < nblocal; m++) {
i = blist[m].i;
@ -225,8 +272,8 @@ void FixHyperGlobal::pre_reverse(int /* eflag */, int /* vflag */)
r0 = blist[m].r0;
estrain = fabs(r-r0) / r0;
if (estrain > emax) {
emax = estrain;
if (estrain > estrain_maxabs) {
estrain_maxabs = estrain;
rmax = r;
r0max = r0;
imax = i;
@ -238,7 +285,7 @@ void FixHyperGlobal::pre_reverse(int /* eflag */, int /* vflag */)
// finds max strain and what proc owns it
// owner = proc that owns that bond
pairme.value = emax;
pairme.value = estrain_maxabs;
pairme.proc = me;
MPI_Allreduce(&pairme,&pairall,1,MPI_DOUBLE_INT,MPI_MAXLOC,world);
owner = pairall.proc;
@ -255,25 +302,34 @@ void FixHyperGlobal::pre_reverse(int /* eflag */, int /* vflag */)
return;
}
// I own the bond with max strain
// compute Vbias and apply force to atoms imax,jmax
// NOTE: logic would need to be different for newton off
// I own the bond with max absolute value of strain
// compute bias force on atoms imax,jmax if strain < q, else zero
// Ebias = current strain = (r-r0) / r0
// Vbias = bias potential = Vmax (1 - Ebias^2/q^2)
// Fbias = bias force as function of strain
// = -dVbias/dEbias = 2 Vmax Ebias / q^2
// Fix = x component of force on atom I
// = Fbias dEbias/dr dr/dxi, dEbias/dr = 1/r0, dr/dxi = delx/r
// dt_boost = time boost factor = exp(Vbias/kT)
// NOTE: logic here would need to be different for newton off
double **f = atom->f;
vbias = fbias = 0.0;
dt_boost = 1.0;
if (emax < qfactor) {
vbias = vmax * (1.0 - emax*emax*invqfactorsq);
fbias = 2.0 * vmax * emax / (qfactor*qfactor * r0max);
if (estrain_maxabs < qfactor) {
//ebias = (rmax-r0max) / r0max;
ebias = fabs(rmax-r0max) / r0max;
vbias = vmax * (1.0 - ebias*ebias*invqfactorsq);
fbias = 2.0 * vmax * ebias * invqfactorsq;
dt_boost = exp(beta*vbias);
delx = x[imax][0] - x[jmax][0];
dely = x[imax][1] - x[jmax][1];
delz = x[imax][2] - x[jmax][2];
fbiasr = fbias / rmax;
fbiasr = fbias / r0max / rmax;
f[imax][0] += delx*fbiasr;
f[imax][1] += dely*fbiasr;
f[imax][2] += delz*fbiasr;
@ -281,13 +337,14 @@ void FixHyperGlobal::pre_reverse(int /* eflag */, int /* vflag */)
f[jmax][0] -= delx*fbiasr;
f[jmax][1] -= dely*fbiasr;
f[jmax][2] -= delz*fbiasr;
} else nobias++;
// output quantities
outvec[0] = vbias;
outvec[1] = dt_boost;
outvec[2] = emax;
outvec[2] = ebias;
outvec[3] = atom->tag[imax];
outvec[4] = atom->tag[jmax];
@ -364,13 +421,16 @@ void FixHyperGlobal::build_bond_list(int natom)
if (atom->nmax > maxold) {
memory->destroy(xold);
memory->destroy(tagold);
memory->destroy(old2now);
maxold = atom->nmax;
memory->create(xold,maxold,3,"hyper/global:xold");
memory->create(tagold,maxold,"hyper/global:tagold");
memory->create(old2now,maxold,"hyper/global:old2now");
}
tagint *tag = atom->tag;
int nall = atom->nlocal + atom->nghost;
nall_old = nall;
for (i = 0; i < nall; i++) {
xold[i][0] = x[i][0];
@ -386,14 +446,11 @@ void FixHyperGlobal::build_bond_list(int natom)
void FixHyperGlobal::grow_bond()
{
// NOTE: could add int arg to do initial large alloc:
// maxbond = maxbond/DELTA * DELTA; maxbond += DELTA;
maxbond += DELTA;
if (maxbond < 0 || maxbond > MAXSMALLINT)
error->one(FLERR,"Fix hyper/local per-processor bond count is too big");
if (maxbond + DELTABOND > MAXSMALLINT)
error->one(FLERR,"Fix hyper/global bond count is too big");
maxbond += DELTABOND;
blist = (OneBond *)
memory->srealloc(blist,maxbond*sizeof(OneBond),"hyper/local:blist");
memory->srealloc(blist,maxbond*sizeof(OneBond),"hyper/global:blist");
}
/* ---------------------------------------------------------------------- */
@ -419,7 +476,7 @@ double FixHyperGlobal::compute_vector(int i)
// 11 vector outputs returned for i = 0-10
// i = 0 = boost factor on this step
// i = 1 = max strain of any bond on this step
// i = 1 = max strain of any bond on this step (positive or negative)
// i = 2 = ID of atom I in max-strain bond on this step
// i = 3 = ID of atom J in max-strain bond on this step
// i = 4 = ave bonds/atom on this step
@ -438,8 +495,9 @@ double FixHyperGlobal::compute_vector(int i)
if (i == 3) return outvec[4];
if (i == 4) {
int allbonds; // NOTE: bigint?
MPI_Allreduce(&nblocal,&allbonds,1,MPI_INT,MPI_SUM,world);
bigint mybonds = nblocal;
bigint allbonds;
MPI_Allreduce(&mybonds,&allbonds,1,MPI_LMP_BIGINT,MPI_SUM,world);
return 2.0*allbonds/atom->natoms;
}

4
src/REPLICA/fix_hyper_global.h
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@ -76,10 +76,12 @@ class FixHyperGlobal : public FixHyper {
// coords and IDs of owned+ghost atoms when bonds were formed
// persists on a proc from one event until the next
int nall_old; // nlocal+nghost for old atoms
int maxold; // allocated size of old atoms
double **xold; // coords of atoms when bonds were formed
tagint *tagold; // IDs of atoms when bonds were formed
tagint *tagold; // IDs of atoms when bonds were forme
int *old2now; // o2n[i] = current local index of old atom I
// MPI data struct for finding bond with max strain via Allreduce

1299
src/REPLICA/fix_hyper_local.cpp
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File diff suppressed because it is too large Load Diff

142
src/REPLICA/fix_hyper_local.h
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@ -45,11 +45,6 @@ class FixHyperLocal : public FixHyper {
int pack_reverse_comm(int, int, double *);
void unpack_reverse_comm(int, int *, double *);
void grow_arrays(int);
void copy_arrays(int, int, int);
int pack_exchange(int, double *);
int unpack_exchange(int, double *);
double memory_usage();
// extra methods visible to callers
@ -62,24 +57,20 @@ class FixHyperLocal : public FixHyper {
double cutbond,qfactor,vmax,tequil,dcut;
double alpha_user; // timescale to apply boostostat (time units)
double alpha; // unitless dt/alpha_user
double boosttarget; // target value of boost
int histoflag;
int lostbond,lostbond_partner;
double lostbond_coeff;
double boost_target; // target value of boost
int checkbias,checkbias_every,checkbias_flag,checkbias_count;
int checkcoeff,checkcoeff_every,checkcoeff_flag,checkcoeff_count;
int setupflag; // 1 during setup, 0 during run
int firstflag; // set for first time bond_build takes place
int nostrainyet; // 1 until maxstrain is first computed
int nboost_running,nobias_running;
int nbias_running,nobias_running;
int nbondbuild;
double time_bondbuild;
bigint starttime;
double sumboostcoeff; // sum of aveboost at every timestep
int allbonds; // sum of bond count on this step
double allboost; // sum of boostcoeff on all bonds on this step
double sumbiascoeff; // sum of aveboost at every timestep
bigint allbonds; // sum of bond count on this step
double allbias; // sum of biascoeff on all bonds on this step
int nnewbond; // running tally of number of new bonds created
int maxbondperatom; // max # of bonds any atom ever has
@ -91,65 +82,88 @@ class FixHyperLocal : public FixHyper {
double mybias;
double maxbondlen; // cummulative max length of any bond
double maxdriftsq; // max distance any atom drifts from original pos
double maxboostcoeff; // cummulative max boost coeff for any bond
double minboostcoeff; // cummulative min boost coeff for any bond
double maxbiascoeff; // cummulative max bias coeff for any bond
double minbiascoeff; // cummulative min bias coeff for any bond
double rmaxever,rmaxeverbig;
int ghost_toofar;
class NeighList *listfull; // full neigh list up to Dcut distance
class NeighList *listhalf; // half neigh list up to pair distance
// both created only when bonds are rebuilt
// list of my owned bonds
// persists on a proc from one event until the next
struct OneBond { // single IJ bond, atom I is owner
int i,j; // current local indices of 2 bond atoms
int iold,jold; // local indices when bonds were formed
double r0; // relaxed bond length
double biascoeff; // biasing coefficient = prefactor Cij
};
struct OneBond *blist; // list of owned bonds
int nblocal; // # of owned bonds
int maxbond; // allocated size of blist
// old data from last timestep bonds were formed
// persists on a proc from one event until the next
// first set of vectors are maxlocal in length
// second set of vectors are maxall in length
int nlocal_old; // nlocal for old atoms
int nall_old; // nlocal+nghost for old atoms
int maxlocal; // allocated size of old local atom vecs
int maxall; // allocated size of old all atom vecs
int *numbond; // # of bonds owned by old owned atoms
int *maxhalf; // bond index for maxstrain bond of old atoms
int *eligible; // 0/1 flag for bias on one of old atom's bonds
double *maxhalfstrain; // strain value for maxstrain bond of old atoms
int *old2now; // o2n[i] = current local index of old atom I
// may be -1 if ghost atom has drifted
tagint *tagold; // IDs of atoms when bonds were formed
// 0 if a ghost atom is not in Dcut neigh list
double **xold; // coords of atoms when bonds were formed
// vectors used to find maxstrain bonds within a local domain
int maxatom; // size of these vectors, nlocal + nghost
double *maxstrain; // max-strain of any bond atom I is part of
// for owned and ghost atoms
double *maxstrain_domain; // max-strain of any neighbor atom J of atom I
// for owned and ghost atoms
tagint *biasflag; // atoms in biased bonds marked with bond partner
// for owned and ghost atoms
// data struct used to persist biascoeffs when bond list is re-created
struct OneCoeff {
double biascoeff;
tagint jtag;
};
struct OneCoeff **clist; // list of bond coeffs for each atom's bonds
int *numcoeff; // # of coeffs per atom
int maxcoeff; // allocate size of clist
int maxcoeffperatom; // allocated # of columns in clist
// list of biased bonds this proc owns
int maxbias; // allocated size of bias list
int nbias; // # of biased bonds I own
int *bias; // index of biased bonds in my bond list
// extra timers
//double timefirst,timesecond,timethird,timefourth;
//double timefifth,timesixth,timeseventh,timetotal;
// data structs for per-atom and per-bond info
// all of these are for current owned and ghost atoms
// except list and old2now are for atom indices at time of last bond build
// private methods
class NeighList *list; // full neigh list up to Dcut distance
// created only when bonds are rebuilt
int *old2now; // o2n[i] = current local index of old atom i
// stored for old owned and ghost atoms
// I = old index when bonds were last created
// old indices are stored in old neighbor list
double **xold; // coords of owned+ghost atoms when bonds created
tagint *tagold; // global IDs of owned+ghost atoms when b created
int maxold; // allocated size of old2now
int maxbond; // allocated size of bonds
int old_nall; // nlocal+nghost when old2now was last setup
struct OneBond { // single IJ bond, atom I is owner
double r0; // original relaxed bond length
double boostcoeff; // boost coefficient
tagint jtag; // global index of J atom in bond IJ
int j; // local index of J atom in bond IJ
};
struct OneBond **bonds; // 2d array of bonds for owned atoms
int *numbond; // number of bonds for each owned atom
double *maxstrain; // max-strain of any bond atom I is part of
// for owned and ghost atoms
double *maxstrain_region; // max-strain of any neighbor atom J of atom I
// for owned and ghost atoms
int *maxstrain_bondindex; // index of max-strain bond of each atom I
// just for owned atoms
tagint *biasflag; // atoms in biased bonds marked with bond partner
// for owned and ghost atoms
// list of boosted bonds that this proc will bias
int maxboost; // allocated size of boost list
int nboost; // # of boosted bonds I own
int *boost; // index of atom I in each boosted bond
// histogramming of bond boost cooeficients
int histo_every,histo_count,histo_print,histo_steps;
double histo_delta,invhisto_delta,histo_lo;
bigint *histo,*allhisto;
void grow_bond();
void grow_coeff();
};
}