Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Efficient Four-Component Dirac-Coulomb-Gaunt Hartree--Fock in Pauli
  Spinor Representation   Four-component Dirac Hartree--Fock is an accurate mean-field method for
treating molecular systems where relativistic effects are important. However,
the computational cost and complexity of the two-electron interaction makes
this method less common, even though we can consider the Dirac Hartree--Fock
Hamiltonian the "ground truth" of electronic structure, barring explicit
quantum-electrodynamical effects. Being able to calculate these effects is then
vital to the design of lower scaling methods for accurate predictions in
computational spectroscopy and properties of heavy element complexes that must
include relativistic effects for even qualitative accuracy. In this work, we
present a Pauli quaternion formalism of maximal component- and spin-separation
for computing the Dirac-Coulomb-Gaunt Hartree--Fock ground state, with a
minimal floating-point-operation count algorithm. This approach also allows one
to explicitly separate different spin physics from the two-body interactions,
such as spin-free, spin-orbit, and the spin-spin contributions. Additionally,
we use this formalism to examine relativistic trends in the periodic table, and
analyze the basis set dependence of atomic gold and gold dimer systems.

23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
10
The categories of this paper are: q-bio
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
25
The categories of this paper are: patt-sol
31
The categories of this paper are: ao-sci
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg