Good Evening Everyone, Thank you for all your great advice. Dr. Roberto Dr. Camps Dr. Haider Dr. Postikov I will consider every piece of advice while doing my calculations. Glad to be finally a part of the SIESTA family.
Regards Yuvam Bhateja On Mon, Jun 8, 2020 at 1:38 AM Andrei Postnikov < [email protected]> wrote: > Dear Yuvam, > if you are new to the code it might be more "robust" to test parts of your > system (just a single-cell graphene; > separately a single-cell oxide; ... ) before making and relaxing a > supercell out of them. > The point is, the choice of basis functions might be critical in Siesta > because it represents a deal > between accuracy you need and the computational effort you would like to > spend, and it is easier > to get some feeling about this compromise when testing small systems. > Exactly for this reason the question "how fast is Siesta", put in general > form, is ill-defined. The answer would depend > on the accuracy needed (i.e., which properties you are after), moreover – > a lot – on the geometry of your system, > number of neighbours to each atom, amount of vacuum in the unit cell, etc. > This said, an automatic relaxation of all crystallographic degrees of > freedom is technically no problem with > *MD.VariableCell *set to *T*, > but, in a complex system, you might need to fix some of parameters (the > lattice parameter of the substrate, or else) > before engaging in a global uncontrollable relaxation which might lead to > weird results. > This said, I'd warn you not to expect too much tutorial-like introductions > from the mailing list > (tutorials being accessible in abundance via the Siesta web page), but > answers to specific questions. > Your inquiry seems mysterious without indicating who "they" used which > scripts for which optimization, > and what was confusing in it. > > Best regards > > Andrei Postnikov > > > ----- Yuvam Bhateja <[email protected]> a écrit : > > > Hello everyone, > > My name is Yuvam and I am an undergraduate student from Kolkata, India. I > am new in siesta and have some experience with softwares like Quantum > ESPRESSO. I want to perform geometrical optimization of my unit cell > (atomic position as well as cell vectors). I have created my custom made > unit cell to accommodate the graphene as well as metal oxide for gas > sensing. I was following a tutorial in which they used scripts for > optimization but I find it very confusing and very unsuitable as varying > all 9 values of lattice vector using loops was very cumbersome. > Can someone help provide any other method in which system does it by its > own like in QE? > And also, how fast is siesta as compared to other codes like QE, as my > system consists of 200-300 atoms and using a cluster with 8 cores and 42 GB > RAM. > > Thank you in advance. > > Regards > Yuvam Bhateja > B.Tech. 3rd year > E&Tc > IIEST Shibpur > > > > -- > SIESTA is supported by the Spanish Research Agency (AEI) and by the > European H2020 MaX Centre of Excellence (http://www.max-centre.eu/) >
-- SIESTA is supported by the Spanish Research Agency (AEI) and by the European H2020 MaX Centre of Excellence (http://www.max-centre.eu/)
