Quantum-ESPRESSO code

The main codes for periodic DFT calculations differ by the choice of basis sets. There are three possibilities atomic orbitals (CRYSTAL, SIESTA, GAUSSIAN codes), plane waves (Vienna ab initio simulation package (VASP), CASTEP, DACAPO, CPMD, Quantum-ESPRESSO codes), or both with a partition of the space between atomic spheres and intermediate regions (APW, LMTO, KKR, WIEN2K codes). We will shortly describe the advantage and disadvantage of the two extreme choices taking CRYSTAL and VASP as representative codes. 

S. Baroni (2005) First-principles codes for computational crystallography in the Quantum-ESPRESSO package. Zeitschrift fiir Kristallogra,phie 220, p. 574... 

D-HMQC correlation experiments, have been used. To support the interpretation of the experimental data, periodic density functional theory calculations together with the GIPAW approach have been used to calculate the H and C chemical shifts. It is found that the shifts calculated with two popular plane wave codes (CASTEP and Quantum ESPRESSO) are in excellent agreement with the experimental results. 

The infra-red and Raman intensities were calculated as in [21] using the PWSCF code, part of the Quantum Espresso package [150]. The Raman spectra obtained for BP and BR models, Fig. 14.16 are drastically different, in particular regarding... 

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