Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread Abderrahmane Reggad
Thank you again Prof Tran and Prof Laurence for your notes and guidenesses. For the procedure to searching the best method giving the best gap I am looking for . Best regards -- Mr: A.Reggad Laboratoire de Génie Physique Université Ibn Khaldoun - Tiaret Algerie

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread tran
As I already wrote previously, 0.06 and 0.1 eV are very close to each other such that it makes absolutely no sense to try to improve further the agreement. Also, as mentioned by L. Marks, you need to figure out if your procedure of searching for the method giving the correct band gap is

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread Abderrahmane Reggad
Thank you Prof Laurence for your precious notes. In my strudy and at the first step, I am intersting to 2 quantities: energy gap and the magnetic moment. I am using 3 methods which are the GGA+U, mBJ and EECE and I want to know the effect of the exchange energy on these 2 quantities through

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread Laurence Marks
I am quite disturbed by some aspects of this thread. Trying to adjust the U, the C in mBJ or something else in order to get a better "fit" to the band gap verges on misleading science. If you are using the band-gap as a calibrant and then intend to look at some other property, e.g. charge transfer

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread Abderrahmane Reggad
Dear prof Tran I am sorry for the error of the gap value . The gap value that i want to reproduce is 0.1 ev . Thank you for your intersting -- Mr: A.Reggad Laboratoire de Génie Physique Université Ibn Khaldoun - Tiaret Algerie ___ Wien mailing list

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread tran
I don't understand. In a previous email you mentioned an experimental gap of 0.1 eV, and now you want to approach 1 eV. So, what is the experimental value? FT On Wednesday 2016-11-23 12:40, Abderrahmane Reggad wrote: Date: Wed, 23 Nov 2016 12:40:55 From: Abderrahmane Reggad

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-23 Thread Abderrahmane Reggad
To Prof Tran Since the unmodified version of Beck-Johnson allows me to get 0.06 ev which corresponds to the value of C parameter equal to the unity (01). I think that to increase of this value would improve the gap value to 1 ev. The question is: Which value for C parameter shall I use to get

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-21 Thread Abderrahmane Reggad
Thank you Prof Tran for your answer You think that this value for gap value is enough . For the other quantity I am interested which is magnetic moment its value is good and doesn't change a lot for all the cases. Best regards -- Mr: A.Reggad Laboratoire de Génie Physique Université Ibn

Re: [Wien] How to get the experimental gap with mBj, PBE+U and EECE methods

2016-11-21 Thread tran
Hi, 0.06 eV from BJ is already very close to experiment and it does not make sense to try to improve further the agreement. Furthermore, the band gap is not the only quantity you should consider for comparison with experiment. FT On Sunday 2016-11-20 22:34, Abderrahmane Reggad wrote: Date: