Dear Robert, There are many ways to define a lattice in input files. So I give you a general expression of the unit cell in matrix form: 2a 0 0 0 2a 0 0 0 10+4a+10
Please remember that, as shown in the diagram on (http://sugino.issp.u-tokyo.ac.jp/esm/index.php?SIESTA%2BESM%20Manual), L is the length of the unit cell along z-axis. Thus L=10 + 4a + 10 is correct. Best regards, Minoru -------------------------------------------------------------------------------------------------------- Minoru Otani National Institute of Advanced Industrial Science and Technology Research Centre for Computational Design of Advanced Functional Materials email : minoru.ot...@aist.go.jp tel : +81-29-861-5202 fax : +81-29-861-3171 --------------------------------------------------------------------------------------------------------- > On Jul 29, 2017, at 0:20, Dr. Robert Molt Jr. > <r.molt.chemical.phys...@gmail.com> wrote: > > Good afternoon, > > I do not understand how the lattice constant is defined in an ESM > calculation of a slab. > > Let's say I have a 2x2x4 slab, and wish to simulate a vacuum on either > side of it. Let us say the unit cells are simple cubic, such that the > height is "a". For a 10 Angstrom vacuum, I assume L/2=10, pursuant to > the diagram on > (http://sugino.issp.u-tokyo.ac.jp/esm/index.php?SIESTA%2BESM%20Manual). > If I do > > assume_isolated=esm > > esm_bc=bc1 > > Is the lattice constant for this situation defined as > > celldm(1)= L/2 + 4a + L/2 > > ? > > Dr. Robert Molt > > Indiana University Perdue University > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum
