Hi, I think better you start with 70 ryd mesh cutoff, and go for k point convergence test, and then see the convergence of total energy or the properties you are interested in.
regards, SKumar IITD On Fri, Jun 1, 2012 at 5:02 PM, Henrik Löfås <[email protected]>wrote: > Dear sir, > > Have you checked which mesh cutoff is actually used? Somewhere in your > output file you will find something like > > InitMesh: Mesh cutoff (required, used) = > > Probably for the ranges where the total energy is constant the "used mesh > cutoff" will have the same value? The mesh cutoff is not a > continuous variable, so when doing the convergence test you have to check > which mesh cutoff is actually used. > > Best regards > Henrik > > > 2012/6/1 mamta chauhan <[email protected]> > >> Dear sir >> >> Thanks for your reply. The problem that i found in selecting mesh cut of >> is that >> the total energy is constant for cetain ranges of mesh cut energy is >> constant like in 70 Ryd to 110 Ryd it is -296.671577. Then from 120 Ryd to >> 140 Ryd it is -296.683935 so on. >> >> Tahnks >> Mamta >> --- On *Fri, 1/6/12, arun dhiman <[email protected]>* wrote: >> >> >> From: arun dhiman <[email protected]> >> Subject: Re: [SIESTA-L] what should be meshcut off energy >> To: "[email protected]" <[email protected]> >> Date: Friday, 1 June, 2012, 4:15 PM >> >> >> You can take value more than 110 Ry for which energy converges >> >> Arun Kumar >> Research Scholar >> Deptt of Physics >> Himachal Pradesh University >> Shimla-5 >> Himachal Pradesh >> India >> ------------------------------ >> *From:* mamta chauhan <[email protected]> >> *To:* [email protected] >> *Sent:* Friday, 1 June 2012, 14:58 >> *Subject:* [SIESTA-L] what should be meshcut off energy >> >> Dear Users >> >> I am applying the convergence test for NaCl crystal.For that I took mesh >> cut off energy from 30 Ryd onwards.I found that after 70 Ryd total energy >> was constant upto 110 Ryd. on increasing the mesh cut off further the total >> energy became constant. I would like to know what value of mesh cut off >> should be selected. >> >> Thanks >> Mamta >> >> >> >
