Dear Stefano, Thank you for your explanation. It is very helpful for us.
Regards, Krishnendu From: [email protected] To: [email protected] Sent: Thursday, November 7, 2024 3:26:55 PM Subject: Re: [QE-users] Speed of valence electrons Dear Krishnendu, the group velocity of an electron associated to a given band is related to the derivative of the energy band w.r.t. the k-vector, which is roughly proportional to band-width and lattice parameters which for valence electrons do not depend strongly on the elements involved. Assuming a simple dispersion like e(k) = -A*cos(k*a) -> v_g = 1/\hbar d e(k)/ d k = A a/ \hbar * sen(k*a) so max v_g ~ A a / \hbar . if you take A ~ 5 eV and a ~ 5 \AA, then max v_g ~ 3 10^7 m/s ~ 0.1 c The behavior of the electrons close to the nuclei is of course affected by relativistic effects for heavy elements, this is why one should use relativistic pseudopotentials. stefano On 07/11/24 06:57, KRISHNENDU MUKHERJEE via users wrote: Hello everyone, Does the valence electrons (those electrons for which the wave function is solved in Quantum Espresso) have non-relativistic speed ? Thanking you, Regards, Krishnendu _______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX ( [ http://www.max-centre.eu/ | www.max-centre.eu ] ) users mailing list [ mailto:[email protected] | [email protected] ] [ https://lists.quantum-espresso.org/mailman/listinfo/users | https://lists.quantum-espresso.org/mailman/listinfo/users ] _______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
