Supposing your cell has a and b on the x-y plane, parallel to x and y respectively, and c parallel to z, try a variable-cell optimization together with
%block GeometryConstraints stress 1 2 4 5 6 %endblock GeometryConstraints (however, check the syntax in the siesta manuals first). The idea is that the cell stresses on the xx, yy, xy, xz and yz stress tensor components do not change. Alternatively, you can always do the E vs c curve with a series of fixed-cell optimizations and extract the value for which c is minimum, given a set of values for a and b. Marcos Vous avez écrit / You have written / Lei ha scritto / Você escreveu... Gregory Geneste > Dear all, > > I would like to know if it is possible to achieve constrained cell > optimization with siesta, for example: optimize the c lattice > parameter while keeping unchanged a and b in an orthorhombic structure. > > Thank you in advance for your suggestions. > > Gregory > -- Dr. Marcos Verissimo Alves Post-Doctoral Fellow Unité de Physico-Chimie et de Physique des Matériaux (PCPM) Université Catholique de Louvain 1 Place Croix du Sud, B-1348 Louvain-la-Neuve Belgique ------ Gort, Klaatu barada nikto. Klaatu barada nikto. Klaatu barada nikto. Free translation: Gort, Google is your friend. Google is your friend. Google is your friend.
