Brajesh Tiwari

7 Questions 28 Answers 0 Followers

Questions related from Brajesh Tiwari

How can I get Fermi-surface by DFT calculations (VASP and Quantum-Espresso)? also projected Fermi-sufaces on different crystallographic planes?

I have electronic structure and density of states for some hexagonal metallic system. I found some visible changes on electronic structure with some change of parameters but not appreciable or...

11 July 2015 4,842 11 View

Why is the upper critical field (Hc2) determined by M-H curve (at lowest possible temperature) and magnetoresistivity (90%of Rn) different?

Why upper critical field (Hc2) of superconductors determined by M-H curve (at lowest possible temperature) and magneto-resistivity (90%of Rn) are different?

11 September 2014 7,704 16 View

How can an irreversibility field Hirr(T) and an upper critical field Hc2(T) from transport measurements on a superconductor be obtained?

I have resistivity data as a function of temperature at different magnetic fields. I want to know the formulas to obtain the irreversibility line (IL) field Hirr(T) and upper critical field Hc2(T)...

24 April 2014 9,011 5 View

Anyone have experience with K-point sampling for electronic and phonon structure calculations?

Please elaborate a bit more on k-point sampling. For example consider a material with space group Pnma (LaCrO3) with Z=4. I use quantum espresso for calculations. I manually put create different...

14 February 2014 4,348 19 View

How can experimentally (BCS) superconducting gap (Delta_k) be determined?

I am new to superconductivity. As I understand Tc (and hence very important) is related to superconducting gap (and type of origin of the gap). I start working on Fe-based superconductor (Pn, Ch)....

25 October 2013 3,082 13 View

How to find out the value of exchange energy (J) by DFT calculations (Quantum ESPRESSO)?

I use Quantum ESPRESSO 4.5 (Abinit also) for electronic structure calculation and (p)DOS for antiferromagnetic materials. I calculated spin polarized DOS for different types of spin arrangements...

20 June 2013 4,352 24 View

Can someone help me to understand the difference between PW and PAW DFT calculations?

I started using Quantum Espresso for density of state calculations. I want to know whether the only difference between PW and PAW is due to pseudo-potential (PP) or the way basic calculation...

07 June 2013 2,175 4 View