Merge pull request #1511 from jdevemy/master (edf64ed1) · Commits · 郑智淋 / lammps

doc/src/compute_pressure.txt

+6 −2

Original line number	Diff line number	Diff line
		@@ -16,12 +16,13 @@ ID, group-ID are documented in "compute"_compute.html command
		pressure = style name of this compute command
		temp-ID = ID of compute that calculates temperature, can be NULL if not needed
		zero or more keywords may be appended
		keyword = {ke} or {pair} or {bond} or {angle} or {dihedral} or {improper} or {kspace} or {fix} or {virial} :ul
		keyword = {ke} or {pair} or {bond} or {angle} or {dihedral} or {improper} or {kspace} or {fix} or {virial} or {pair/hybrid} :ul

		[Examples:]

		compute 1 all pressure thermo_temp
		compute 1 all pressure NULL pair bond :pre
		compute 1 all pressure NULL pair bond
		compute 1 all pressure NULL pair/hybrid lj/cut :pre

		[Description:]

		@@ -67,6 +68,9 @@ extra keywords are listed, then only those components are summed to
		compute temperature or ke and/or the virial. The {virial} keyword
		means include all terms except the kinetic energy {ke}.

		The {pair/hybrid} keyword means to only include contribution
		from a sub-style in a {hybrid} or {hybrid/overlay} pair style.

		Details of how LAMMPS computes the virial efficiently for the entire
		system, including for many-body potentials and accounting for the
		effects of periodic boundary conditions are discussed in

src/compute_pressure.cpp

+53 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include "fix.h"
		#include "force.h"
		#include "pair.h"
		#include "pair_hybrid.h"
		#include "bond.h"
		#include "angle.h"
		#include "dihedral.h"
		@@ -65,6 +66,7 @@ ComputePressure::ComputePressure(LAMMPS lmp, int narg, char *arg) :

		// process optional args

		pairhybridflag = 0;
		if (narg == 4) {
		keflag = 1;
		pairflag = 1;
		@@ -78,6 +80,37 @@ ComputePressure::ComputePressure(LAMMPS lmp, int narg, char *arg) :
		int iarg = 4;
		while (iarg < narg) {
		if (strcmp(arg[iarg],"ke") == 0) keflag = 1;
		else if (strcmp(arg[iarg],"pair/hybrid") == 0) {
		int n = strlen(arg[++iarg]) + 1;
		if (lmp->suffix) n += strlen(lmp->suffix) + 1;
		pstyle = new char[n];
		strcpy(pstyle,arg[iarg++]);

		nsub = 0;

		if (narg > iarg) {
		if (isdigit(arg[iarg][0])) {
		nsub = force->inumeric(FLERR,arg[iarg]);
		++iarg;
		if (nsub <= 0)
		error->all(FLERR,"Illegal compute pressure command");
		}
		}

		// check if pair style with and without suffix exists

		pairhybrid = (Pair *) force->pair_match(pstyle,1,nsub);
		if (!pairhybrid && lmp->suffix) {
		strcat(pstyle,"/");
		strcat(pstyle,lmp->suffix);
		pairhybrid = (Pair *) force->pair_match(pstyle,1,nsub);
		}

		if (!pairhybrid)
		error->all(FLERR,"Unrecognized pair style in compute pressure command");

		pairhybridflag = 1;
		}
		else if (strcmp(arg[iarg],"pair") == 0) pairflag = 1;
		else if (strcmp(arg[iarg],"bond") == 0) bondflag = 1;
		else if (strcmp(arg[iarg],"angle") == 0) angleflag = 1;
		@@ -132,6 +165,20 @@ void ComputePressure::init()
		temperature = modify->compute[icompute];
		}

		// recheck if pair style with and without suffix exists

		if (pairhybridflag) {
		pairhybrid = (Pair *) force->pair_match(pstyle,1,nsub);
		if (!pairhybrid && lmp->suffix) {
		strcat(pstyle,"/");
		strcat(pstyle,lmp->suffix);
		pairhybrid = (Pair *) force->pair_match(pstyle,1,nsub);
		}

		if (!pairhybrid)
		error->all(FLERR,"Unrecognized pair style in compute pressure command");
		}

		// detect contributions to virial
		// vptr points to all virial[6] contributions

		@@ -139,6 +186,7 @@ void ComputePressure::init()
		nvirial = 0;
		vptr = NULL;

		if (pairhybridflag && force->pair) nvirial++;
		if (pairflag && force->pair) nvirial++;
		if (bondflag && atom->molecular && force->bond) nvirial++;
		if (angleflag && atom->molecular && force->angle) nvirial++;
		@@ -151,6 +199,11 @@ void ComputePressure::init()
		if (nvirial) {
		vptr = new double*[nvirial];
		nvirial = 0;
		if (pairhybridflag && force->pair) {
		PairHybrid ph = (PairHybrid ) force->pair;
		ph->no_virial_fdotr_compute = 1;
		vptr[nvirial++] = pairhybrid->virial;
		}
		if (pairflag && force->pair) vptr[nvirial++] = force->pair->virial;
		if (bondflag && force->bond) vptr[nvirial++] = force->bond->virial;
		if (angleflag && force->angle) vptr[nvirial++] = force->angle->virial;

src/compute_pressure.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -41,10 +41,16 @@ class ComputePressure : public Compute {
		Compute *temperature;
		char *id_temp;
		double virial[6];
		int pairhybridflag;
		class Pair *pairhybrid;
		int keflag,pairflag,bondflag,angleflag,dihedralflag,improperflag;
		int fixflag,kspaceflag;

		void virial_compute(int, int);

		private:
		char *pstyle;
		int nsub;
		};

		}

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