thank for your reply, but cellside: fixes the unit-cell side lengths to their initial values (not implemented yet). cellangle: xes the unit-cell angles to their initial values (not implemented yet).
so my meaning 1. is that my consstr.f is right or not: 2. should i use MD.VariableCell =T ans well as the %block GeometryConstraints at the same time? On Sun, Jun 15, 2014 at 2:44 AM, Mostafa Shabani < [email protected]> wrote: > Hi > use GeometryConstraints > fore example > > %block GeometryConstraints > cellside c > cellangle alpha beta gam > position from -1 to -10 > rigid 1 2 > center 1 2 0.0 0.0 1.0 > stress 4 5 6 > routine constr > %endblock GeometryConstraints > > > On Sun, Jun 15, 2014 at 1:04 AM, xu yuehua <[email protected]> wrote: > >> >> Hi,all: >> >> i want to relax the geometry of the cell, but i only need relax the c >> cellside, and fix the a, b side. >> >> according to the manual; >> >> i rewrite the cinstr.f the code is >> >> *! and J.M.Soler, 1996-2006.* >> *! * >> *! Use of this software constitutes agreement with the full conditions* >> *! given in the SIESTA license, as signed by all legitimate users.* >> *!* >> *c $Id: constr.f,v 1.6 2003/06/23 09:46:16 ordejon Exp $* >> >> * subroutine constr( cell, na, isa, amass, xa, stress, fa, ntcon )* >> *c ****************************************************************** >> *c User-written routine to implement specific geometric constraints,* >> *c by orthogonalizing the forces and stress to undesired changes.* >> *c Arguments:* >> *c real*8 cell(3,3) : input lattice vectors (Bohr)* >> *c integer na : input number of atoms* >> *c integer isa(na) : input species indexes* >> *c real*8 amass(na) : input atomic masses* >> *c real*8 xa(3,na) : input atomic cartesian coordinates (Bohr)* >> *c real*8 stress( 3,3) : input/output stress tensor (Ry/Bohr**3)* >> *c real*8 fa(3,na) : input/output atomic forces (Ry/Bohr)* >> *c integer ntcon : total number of positions constr. imposed* >> *c ****************************************************************** >> * implicit none* >> * integer na, isa(na), ntcon* >> * double precision amass(na), cell(3,3), fa(3,na),* >> * . stress(3,3), xa(3,na)* >> >> *c Write here your problem-specific code.* >> * stress(1,2) = 0.0d0* >> * stress(1,3) = 0.0d0* >> * stress(1,1) = 0.0d0* >> >> * stress(2,1) = 0.0d0* >> * stress(2,2) = 0.0d0* >> * stress(2,3) = 0.0d0* >> >> * stress(3,1) = 0.0d0* >> * stress(3,2) = 0.0d0* >> *c stress(3,3) = 0.0d0* >> * return* >> >> * end* >> >> am i right? >> >> my question is in the fdf input file, Should i set the MD.VariableCell =T >> >> and also Set >> %block GeometryConstraints >> routine constr >> %endblock GeometryConstraints >> >> >> or set the latter only, let the MD.VariableCell =F >> >> i need your help >> >> thanks very much! >> -- >> unl chemistry department >> > > -- lalala lalala
