Re: [Wien] Minimization before Volume Optimization ?

2016-11-11 Thread Abderrahmane Reggad
Thanks Mr pieper for the rich information . So , I have to minimize the atomic positions of the new low symmetry structure with respect to internal forces, or energy. Now the question is: Is there any difference between using the internal forces or the energy ? or it's the same ? -- Mr: A.Regga

Re: [Wien] Minimization before Volume Optimization ?

2016-11-11 Thread pieper
sgroup (or other scripts in the initialization) does'nt change the positions of the atoms, it changes the basis used to describe the positions. 'Optimization' is done with respect to internal forces, or energy, both unknown at that step. Good luck Martin Pieper --- Dr. Martin Pieper Karl-Fra

Re: [Wien] Minimization before Volume Optimization ?

2016-11-11 Thread Abderrahmane Reggad
Now I want to know if a low symmetry structure (orthorhombic) derived from its high symmetry structure (hexagonal NiAs )has its atomic positions optimized (because they are created with sgroup program) or need to be optimized . Best regards -- Mr: A.Reggad Laboratoire de Génie Physique Universi

Re: [Wien] Minimization before Volume Optimization ?

2016-11-11 Thread Abderrahmane Reggad
Thank your Gerhard and Dobysheva for your answers * Do you think the ground state is the state with arbitrarily choosen positions of the atoms ? - No,of course bur I want to be sure * When you make a calculation you take _a_model_ instead of an actual sample. The choice of the model usually tak

Re: [Wien] Minimization before Volume Optimization ?

2016-11-10 Thread Lyudmila Dobysheva
11.11.2016 02:06, Abderrahmane Reggad wrote: my question is about the determination of the magnetic ground state . Is it necessary the minimization of the atomic positions for this purpose? When you make a calculation you take _a_model_ instead of an actual sample. The choice of the model usua

Re: [Wien] Minimization before Volume Optimization ?

2016-11-10 Thread Fecher, Gerhard
.ac.at] im Auftrag von Abderrahmane Reggad [jazai...@gmail.com] Gesendet: Donnerstag, 10. November 2016 23:06 An: wien@zeus.theochem.tuwien.ac.at Betreff: Re: [Wien] Minimization before Volume Optimization ? Dear Gerhard Yes I did but my question is about the determination of the magnetic ground s

Re: [Wien] Minimization before Volume Optimization ?

2016-11-10 Thread Abderrahmane Reggad
Dear Gerhard Yes I did but my question is about the determination of the magnetic ground state . Is it necessary the minimization of the atomic positions for this purpose? Best regards -- Mr: A.Reggad Laboratoire de Génie Physique Université Ibn Khaldoun - Tiaret Algerie __

Re: [Wien] Minimization before Volume Optimization ?

2016-11-10 Thread Fecher, Gerhard
gad [jazai...@gmail.com] Gesendet: Donnerstag, 10. November 2016 21:59 An: wien@zeus.theochem.tuwien.ac.at Betreff: Re: [Wien] Minimization before Volume Optimization ? Hello again I am still waiting for any answer for my query . every effort will be helful Best regards -- Mr: A.Reggad Laboratoir

Re: [Wien] Minimization before Volume Optimization ?

2016-11-10 Thread Abderrahmane Reggad
Hello again I am still waiting for any answer for my query . every effort will be helful Best regards -- Mr: A.Reggad Laboratoire de Génie Physique Université Ibn Khaldoun - Tiaret Algerie ___ Wien mailing list Wien@zeus.theochem.tuwien.ac.at http://z