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6 votes

Which formalism is better suited to model a crystal with defects: Hartree–Fock, Kohn–Sham, or something else?

I would like to add a few aspects to the answer of wzkchem5. Considering local or semilocal xc functionals for the KS equations, one difference between HF and KS is that HF is computationally more ...
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7 votes

Which formalism is better suited to model a crystal with defects: Hartree–Fock, Kohn–Sham, or something else?

Let me first clarify a few things. Whether a calculation is Kohn-Sham or Hartree-Fock has nothing to do with whether the calculation is periodic or not. In fact, both Kohn-Sham and Hartree-Fock can ...
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3 votes

Raman Spectra in Quantum Espresso

It would seem that if a crystal system has no Raman-active modes, QE simply won't print out the Raman intensities. To verify this, I tried to simulate the Raman activity of $\ce{NaCl}$ (also a member ...
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4 votes

How are the exponents in a STO-nG basis set obtained?

You are right that the STO-nG basis sets are optimized separately for each individual element (as an isolated atom, rather than as an ion or an atom within a bigger molecule). The exponents are ...
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5 votes

ORCA: Dipole moment of LiH from SP calculation

Dipole moment in Quantum Mechanicl I dare to expand the answer of wzkchem5, taking into account how I understood (with some math). The dipole moment of molecular system (which is described by wave ...
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9 votes
Accepted

ORCA: Dipole moment of LiH from SP calculation

As suggested by Tyberius, I now expand my comment into an answer. The true charge density of a molecule is a sum of nuclear and electronic contributions. While the former is a sum of delta functions (...
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3 votes

Solving the Schrödinger equation as a service?

Good Chemistry A new company called Good Chemistry, a spinoff company of 1QBit, has released a beta-version of their QEMIST Cloud service which purports to do exactly what you're asking about. From ...
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