This module contains the definitions of constants used in Wannier90 - both numerical constants such as pi and numerical convergence tolerances, but also physical constant such as the speed of light
Values of the fundamental constants are taken from http://physics.nist.gov/cuu/Constants/index.html By default CODATA2010 is used (CODATA2006 can be selected using an appropriate compile-time flag (see INSTALL guide)
Type | Visibility | Attributes | Name | Initial | |||
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integer, | public, | parameter | :: | i64 | = | selected_int_kind(15) | 64bit integer |
integer, | public, | parameter | :: | dp | = | kind(1.0d0) | double precision |
real(kind=dp), | public, | parameter | :: | pi | = | 3.141592653589793238462643383279_dp |
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real(kind=dp), | public, | parameter | :: | twopi | = | 2*pi |
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complex(kind=dp), | public, | parameter | :: | cmplx_i | = | (0.0_dp, 1.0_dp) | i as a complex variable |
complex(kind=dp), | public, | parameter | :: | cmplx_0 | = | (0.0_dp, 0.0_dp) | 0 as a complex variable |
complex(kind=dp), | public, | parameter | :: | cmplx_1 | = | (1.0_dp, 0.0_dp) | 1 as a complex variable |
real(kind=dp), | public, | parameter | :: | eps2 | = | 1.0e-2_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | eps5 | = | 1.0e-5_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | eps6 | = | 1.0e-6_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | eps7 | = | 1.0e-7_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | eps8 | = | 1.0e-8_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | eps10 | = | 1.0e-10_dp | numerical convergence constant |
real(kind=dp), | public, | parameter | :: | smearing_cutoff | = | 10._dp | Cutoff for the smearing functions |
real(kind=dp), | public, | parameter | :: | min_smearing_binwidth_ratio | = | 2._dp | Don't smear but simply add the contribution to the relevant bin if the smearing/binwidth ratio is smaller than this value |
real(kind=dp), | public, | parameter | :: | elem_charge_SI | = | 1.602176487e-19_dp | e |
real(kind=dp), | public, | parameter | :: | elec_mass_SI | = | 9.10938215e-31_dp |
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real(kind=dp), | public, | parameter | :: | hbar_SI | = | 1.054571628e-34_dp |
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real(kind=dp), | public, | parameter | :: | k_B_SI | = | 1.3806504e-23_dp |
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real(kind=dp), | public, | parameter | :: | bohr_magn_SI | = | 927.400915e-26_dp |
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real(kind=dp), | public, | parameter | :: | eps0_SI | = | 8.854187817e-12_dp |
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real(kind=dp), | public, | parameter | :: | speedlight_SI | = | 299792458.0_dp |
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real(kind=dp), | public, | parameter | :: | eV_au | = | 3.674932540e-2_dp | eV in atomic units |
real(kind=dp), | public, | parameter | :: | eV_seconds | = | 6.582119e-16_dp | Electron Volt in seconds |
real(kind=dp), | public, | parameter | :: | bohr_angstrom_internal | = | 0.52917720859_dp | Bohr to |
character(len=75), | public, | parameter | :: | constants_version_str1 | = | "-> Using CODATA 2006 constant values" | |
character(len=75), | public, | parameter | :: | constants_version_str2 | = | " (http://physics.nist.gov/cuu/Constants/index.html)" | |
real(kind=dp), | public, | parameter | :: | bohr | = | bohr_angstrom_internal | |
character(len=75), | public, | parameter | :: | bohr_version_str | = | "-> Using Bohr value from CODATA" |