from __future__ import annotations
import numpy as np
from ..units import radians_per_fs_to_THz
from .band import Band
[docs]class QPoint:
"""Representation of a single q-point and properties
The bands can be accessed by e.g. `qp[2]` to get band index 2 in the form
of a :class:`dynasor.modes.band.Band` object
"""
def __init__(self, q, mp):
self._mp = mp
self._q = q
# Dunders
def __str__(self):
string = f"""### q-point ###
Index: {self.index}
Reduced: {self.q_reduced}
Cartesian: [{self.q_cartesian[0]:.2f}, {self.q_cartesian[1]:.2f}, {self.q_cartesian[2]:.2f}] rad/Å
Wavenumber: {self.wavenumber:.2f} rad/Å
Wavelength: {self.wavelength:.2f} Å
q-minus: {self.q_minus.index} {self.q_minus.q_reduced}
Real: {self.is_real}"""
string += ("""
Omegas: [""" + ', '.join(f'{t * radians_per_fs_to_THz:.2f}' for t in self.omegas) + '] THz')
return string
def __repr__(self):
return str(self)
def __getitem__(self, s):
if s >= self._mp.primitive.n_atoms * 3:
raise IndexError
return Band(self.index, s, self._mp)
@property
def q_minus(self) -> QPoint:
"""The corresponding counter-propagating mode"""
return self._mp[self._mp.q_minus[self.index]]
@property
def polarizations(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.polarizations[self.index]
@property
def omegas(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.omegas[self.index]
@property
def is_real(self):
"""If the q-point has purely real mode coordinates, 'q=-q'"""
return self.index == self.q_minus.index
@property
def index(self):
"""q-point index corresponding to :class:`dynasor.ModeProjector.q_reduced`"""
return self._q
@property
def wavenumber(self):
"""Wavenumber of mode in rad/Å"""
return np.linalg.norm(self._mp.q_cartesian[self.index])
@property
def wavelength(self):
"""Wavelength of mode in Å"""
return np.inf if self.wavenumber == 0 else 2*np.pi / self.wavenumber
@property
def q_reduced(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.q_reduced[self.index]
@property
def q_cartesian(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.q_cartesian[self.index]
@property
def eigenmodes(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.eigenmodes[self.index]
@property
def potential_energies(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.potential_energies[self.index]
@property
def kinetic_energies(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.kinetic_energies[self.index]
@property
def virial_energies(self):
"""Slice, see :class:`dynasor.ModeProjector`"""
return self._mp.virial_energies[self.index]