New options adaptstep and halfstepback in adaptglok. Adapted documentation. (bf85b04a) · Commits · 郑智淋 / lammps

doc/src/min_modify.txt

+9 −3

Changes for doc/src/min_modify.txt: 9 added lines, 3 removed lines.
Original line number	Diff line number	Diff line
		@@ -19,14 +19,17 @@ keyword = {dmax} or {line} or {delaystep} or {dt_grow} or {dt_shrink}
		max = maximum distance for line search to move (distance units)
		{line} value = {backtrack} or {quadratic} or {forcezero}
		backtrack,quadratic,forcezero = style of linesearch to use
		{integrator} value = {eulerimplicit} or {eulerexplicit} or {verlet} or {leapfrog} for adaptglok :pre
		{delaystep} value = {int} for adaptglok
		{dt_grow} value = {float} for adaptglok
		{dt_shrink} value = {float} for adaptglok
		{alpha0} value = {float} for adaptglok
		{alpha_shrink} value = {float} for adaptglok
		{tmax} value = {float} for adaptglok
		{tmin} value = {float} for adaptglok :pre
		{tmin} value = {float} for adaptglok
		{integrator} value = {eulerimplicit} or {eulerexplicit} or {verlet}
		or {leapfrog} for adaptglok
		{adaptstep} arg = {yes} or {no} for adaptglok
		{halfstepback} value = {yes} or {no} for adaptglok :pre
		:ule

		[Examples:]
		@@ -79,6 +82,9 @@ to optimize the relaxation: {integrator}, {delaystep}, {dt_grow}, {dt_shrink},
		{alpha0}, {alpha_shrink}, {tmax} and {tmin}. The default values have
		been chosen to be reliable in most cases, but one could be willing
		to adapt them for particular cases.
		In particular for debugging purpose, it is possible to switch off the
		variable timestep and the backstep when downhill, by using {adaptstep}
		and {halfstepback}.

		[Restrictions:] none

		@@ -90,4 +96,4 @@ to adapt them for particular cases.

		The option defaults are dmax = 0.1, line = quadratic, integrator = eulerimplicit, delaystep = 20,
		dt_grow = 1.1, dt_shrink = 0.5, alpha0 = 0.25, alpha_shrink = 0.99,
		tmax = 2.0 and tmin = 0.02.
		tmax = 2.0, tmin = 0.02, adaptstep = yes and halfstepback = yes.

doc/src/min_style.txt

+2 −2

Changes for doc/src/min_style.txt: 2 added lines, 2 removed lines.
Original line number	Diff line number	Diff line
		@@ -64,8 +64,8 @@ a minimization.
		Style {adaptglok} is a re-implementation of the style {fire} to better
		fit the published and unpublished optimizations of the method described
		in "(Bitzek)"_#Bitzek. It includes a temporization of the variable
		timestep, a backstep when uphill and different integration
		schemes (Euler, Leap Frog, Velocity-Verlet).
		timestep, a backstep when downhill and different integration
		schemes.

		Either the {quickmin} and {fire} styles are useful in the context of
		nudged elastic band (NEB) calculations via the "neb"_neb.html command.

src/min.cpp

+14 −0

Changes for src/min.cpp: 14 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -63,6 +63,8 @@ Min::Min(LAMMPS *lmp) : Pointers(lmp)
		tmax = 2.0;
		tmin = 0.02;
		integrator = 0;
		halfstepback_flag = 1;
		adaptstep_flag = 1;

		elist_global = elist_atom = NULL;
		vlist_global = vlist_atom = NULL;
		@@ -680,6 +682,18 @@ void Min::modify_params(int narg, char **arg)
		if (iarg+2 > narg) error->all(FLERR,"Illegal min_modify command");
		tmin = force->numeric(FLERR,arg[iarg+1]);
		iarg += 2;
		} else if (strcmp(arg[iarg],"halfstepback") == 0) {
		if (iarg+2 > narg) error->all(FLERR,"Illegal min_modify command");
		if (strcmp(arg[iarg+1],"yes") == 0) halfstepback_flag = 1;
		else if (strcmp(arg[iarg+1],"no") == 0) halfstepback_flag = 0;
		else error->all(FLERR,"Illegal min_modify command");
		iarg += 2;
		} else if (strcmp(arg[iarg],"adaptstep") == 0) {
		if (iarg+2 > narg) error->all(FLERR,"Illegal min_modify command");
		if (strcmp(arg[iarg+1],"yes") == 0) adaptstep_flag = 1;
		else if (strcmp(arg[iarg+1],"no") == 0) adaptstep_flag = 0;
		else error->all(FLERR,"Illegal min_modify command");
		iarg += 2;
		} else if (strcmp(arg[iarg],"integrator") == 0) {
		if (iarg+2 > narg) error->all(FLERR,"Illegal min_modify command");
		if (strcmp(arg[iarg+1],"eulerimplicit") == 0) integrator = 0;

src/min.h

+2 −0

Changes for src/min.h: 2 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -63,6 +63,8 @@ class Min : protected Pointers {
		double alpha0,alpha_shrink; // mixing velocities+forces coefficient (adaptglok)
		double tmax,tmin; // timestep max, min (adaptglok)
		int integrator; // choose the style of time integrator (adaptglok)
		int halfstepback_flag; // 1: half step backward when v.f <= 0.0 (adaptglok)
		int adaptstep_flag; // 1: variable timestep, 0: constant (adaptglok)

		int nelist_global,nelist_atom; // # of PE,virial computes to check
		int nvlist_global,nvlist_atom;

src/min_adaptglok.cpp

+4 −2

Changes for src/min_adaptglok.cpp: 4 added lines, 2 removed lines.
Original line number	Diff line number	Diff line
		@@ -184,7 +184,7 @@ int MinAdaptGlok::iterate(int maxiter)
		if (fdotfall <= 1e-20) scale2 = 0.0;
		else scale2 = alpha * sqrt(vdotvall/fdotfall);

		if (ntimestep - last_negative > delaystep) {
		if (ntimestep - last_negative > delaystep && adaptstep_flag) {
		dt = MIN(dt*dt_grow,dtmax);
		update->dt = dt;
		alpha *= alpha_shrink;
		@@ -201,7 +201,7 @@ int MinAdaptGlok::iterate(int maxiter)
		} else {
		last_negative = ntimestep;
		// Limit decrease of timestep
		if (ntimestep - ntimestep_fire > delaystep) {
		if (ntimestep - ntimestep_fire > delaystep && adaptstep_flag) {
		alpha = alpha0;
		if (dt > dtmin) {
		dt *= dt_shrink;
		@@ -209,11 +209,13 @@ int MinAdaptGlok::iterate(int maxiter)
		}
		}
		double **x = atom->x;
		if (halfstepback_flag) {
		for (int i = 0; i < nlocal; i++) {
		x[i][0] -= 0.5 * dtv * v[i][0];
		x[i][1] -= 0.5 * dtv * v[i][1];
		x[i][2] -= 0.5 * dtv * v[i][2];
		}
		}
		for (int i = 0; i < nlocal; i++)
		v[i][0] = v[i][1] = v[i][2] = 0.0;
		}

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