I can not find any mistake in your calculations. Maybe you can use a different base. But, how do you know that the correct angle is 96^o and not 99^o ? Is this difference very important for you? I mean several theoretical approaches may have some differences with respect to the experiment, but they sill can be used to derive useful results.
> Dear Siesta users, > I'm trying to perform the optimization of an unit cell composed by four > molecules of the a neurotransmitter (for reference, the type of system is > similar to: J. Appl. Phys. 129, 234702 (2021); > https://urldefense.com/v3/__https://doi.org/10.1063/5.0054383__;!!D9dNQwwGXtA!VFwPgy7nicqJ4IHnnPgVwKcU8-H_FqWGOqP4Sbhw1XjlP5vvlaNC3lgewdXOsPI0ygo0IQ2_Io4V3TxayhNCrw$ > ). It's a monoclinic crystal with equal alpha and gamma angles. > When I run the geometry optimization, the result is always the shortening > of the a, b, c, alpha and gamma, and the increase of beta (from 96° to > 98-99°). However, it is expected that the a, b, and c parameters to > increase. I thought it could be something related with the > pseudopotencial, and downloaded the PBE Pseudopotencial from different > sources, but nothing change. > Could someone help me to understand what's wrong? > I'm including the parameters I used to control the simulation > #MD.TypeOfRun CG MD.Steps > 2000 MD.MaxDispl 0.001 Bohr MD.MaxForceTol > 0.01 eV/Ang MD.VariableCell T > MD.MaxStressTol 0.02 GPa MD.TargetPressure 0.0 GPa > > # WriteCoorStep TWriteForces TWriteMDHistory > TWriteCoorInitial T > # DM.UseSaveDM TMD.UseSaveXV TMD.UseSaveCG > T > Thank you for your help > -- > SIESTA is supported by the Spanish Research Agency (AEI) and by the > European H2020 MaX Centre of Excellence > (https://urldefense.com/v3/__http://www.max-centre.eu/__;!!D9dNQwwGXtA!UqJJRS4uVg7t-Dbd_eAjfVnwWZ1t2C6FcN2aIQ3zMnpwP4Ll9vMlgtpcq4qP80YzOBfKsToR3FKvor_wWQ0$ > ) > ********************************************************* Dr Zacharias G. Fthenakis **********************************************************
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
