#
# Description of the basis set:
#
# Double-zeta plus polarization for the valence states.
# Single-zeta for the semicore states.
#
# For La: 
#    5s: one radial function
#    5p: one radial function
#    6s: two radial functions
#    5d: two radial functions
#    6p: one radial function
# For Al:
#    3s: two radial functions
#    3p: two radial functions
#    3d: one radial function
# For O:
#    2s: two radial functions
#    2p: two radial functions
#    3d: one radial function
#
# The basis set has been optimized for the bulk cubic LaAlO3 at the
# experimental lattice constant (3.790 Ang) with a pressure of 0.03 GPa
# The basis set for O has been frozen to the optimized one for SrTiO3
#
#------------------------------------------------------------------------------
#
# Tests performed on the basis set:
# 
#------------------------------------------------------------------------------
#
# Theoretical lattice constant of the cubic structure:
# 3.805406 Ang = 7.1912731258385767 bohr
# Compared with the experimental lattice constant, 3.790 Ang,
# the deviation is of +0.4%.
#
#------------------------------------------------------------------------------
# 
# Total susceptibility at the theoretical lattice constant,
# after relaxing the structure under a field along z, 
# of 0.01 V/Ang (= 0.000194467 Ha/bohr)
# we get a polarization of:
# 
# finief: Total polarization along the cartesian directions (electrons*bohr)
# finief:   -53.935291  -53.935291  -53.810320
#
# chi = Delta P / Delta E
# 
# P(E=0.01 V/Ang) = (-53.810320 - (7.5 * 7.1912731258385767) ) /
#                   (7.1912731258385767)**3 =
#                   0.00033404401416022147 electrons / bohr**2
# P(E=0.00 V/Ang) = -53.933833 electrons * bohr
#
# Delta P = (-53.810320 - -53.933833) = 0.123513 electrons * bohr
#         
# Delta P = 0.123513 / (7.1912731258385767)**3 electrons/bohr**2 = 
# 
# chi = 0.00033212022192711382 / 0.000194467 = 1.7078
# epsilon_0 = 1 + 4 pi chi = 22.4614
#
#-----------------------------------------------------------------------------
#
# Phonons at Gamma at the theoretical lattice constant
# Force constant matrix computed with finite differences of 0.02 bohrs
#
# SIESTA                Others (data provided by Nick Bristowe)
# 184 cm^-1             167 cm^-1
# 304 cm^-1             290 cm^-1
# 419 cm^-1             412 cm^-1
# 650 cm^-1             648 cm^-1
#
#------------------------------------------------------------------------------
#
# Eggbox effect:
# Delta E after displaced rigidly the system:
# 0.000273 eV
# Delta f after displaced rigidly the system:
# 0.010266 eV/Ang
#
#------------------------------------------------------------------------------

