Coverage for /builds/kinetik161/ase/ase/calculators/lammps/unitconvert.py: 100.00%

1"""LAMMPS has the options to use several internal units (which can be different 

2from the ones used in ase). Mapping is therefore necessary. 

3 

4See: https://lammps.sandia.gov/doc/units.html 

5 """ 

6 

7from ase import units 

8 

9from . import unitconvert_constants as u 

10 

11# !TODO add reduced Lennard-Jones units? 

12 

13# NOTE: We assume a three-dimensional simulation here! 

14DIM = 3.0 

15 

16UNITSETS = {} 

17 

18UNITSETS["ASE"] = dict( 

19 mass=1.0 / units.kg, 

20 distance=1.0 / units.m, 

21 time=1.0 / units.second, 

22 energy=1.0 / units.J, 

23 velocity=units.second / units.m, 

24 force=units.m / units.J, 

25 pressure=1.0 / units.Pascal, 

26 charge=1.0 / units.C, 

27) 

28 

29UNITSETS["real"] = dict( 

30 mass=u.gram_per_mole_si, 

31 distance=u.angstrom_si, 

32 time=u.femtosecond_si, 

33 energy=u.kcal_per_mole_si, 

34 velocity=u.angstrom_per_femtosecond_si, 

35 force=u.kcal_per_mole_angstrom_si, 

36 torque=u.kcal_per_mole_si, 

37 temperature=u.kelvin_si, 

38 pressure=u.atmosphere_si, 

39 dynamic_viscosity=u.poise_si, 

40 charge=u.e_si, 

41 dipole=u.electron_angstrom_si, 

42 electric_field=u.volt_per_angstrom_si, 

43 density=u.gram_si / u.centimeter_si ** DIM, 

44) 

45 

46UNITSETS["metal"] = dict( 

47 mass=u.gram_per_mole_si, 

48 distance=u.angstrom_si, 

49 time=u.picosecond_si, 

50 energy=u.ev_si, 

51 velocity=u.angstrom_per_picosecond_si, 

52 force=u.ev_per_angstrom_si, 

53 torque=u.ev_si, 

54 temperature=u.kelvin_si, 

55 pressure=u.bar_si, 

56 dynamic_viscosity=u.poise_si, 

57 charge=u.e_si, 

58 dipole=u.electron_angstrom_si, 

59 electric_field=u.volt_per_angstrom_si, 

60 density=u.gram_si / u.centimeter_si ** DIM, 

61) 

62 

63UNITSETS["si"] = dict( 

64 mass=u.kilogram_si, 

65 distance=u.meter_si, 

66 time=u.second_si, 

67 energy=u.joule_si, 

68 velocity=u.meter_per_second_si, 

69 force=u.newton_si, 

70 torque=u.joule_si, 

71 temperature=u.kelvin_si, 

72 pressure=u.pascal_si, 

73 dynamic_viscosity=u.pascal_si * u.second_si, 

74 charge=u.coulomb_si, 

75 dipole=u.coulomb_meter_si, 

76 electric_field=u.volt_per_meter_si, 

77 density=u.kilogram_si / u.meter_si ** DIM, 

78) 

79 

80UNITSETS["cgs"] = dict( 

81 mass=u.gram_si, 

82 distance=u.centimeter_si, 

83 time=u.second_si, 

84 energy=u.erg_si, 

85 velocity=u.centimeter_per_second_si, 

86 force=u.dyne_si, 

87 torque=u.dyne_centimeter_si, 

88 temperature=u.kelvin_si, 

89 pressure=u.dyne_per_centimetersq_si, # or barye =u. 1.0e-6 bars 

90 dynamic_viscosity=u.poise_si, 

91 charge=u.statcoulomb_si, # or esu (4.8032044e-10 is a proton) 

92 dipole=u.statcoulomb_centimeter_si, # =u. 10^18 debye, 

93 electric_field=u.statvolt_per_centimeter_si, # or dyne / esu 

94 density=u.gram_si / (u.centimeter_si ** DIM), 

95) 

96 

97UNITSETS["electron"] = dict( 

98 mass=u.amu_si, 

99 distance=u.bohr_si, 

100 time=u.femtosecond_si, 

101 energy=u.hartree_si, 

102 velocity=u.bohr_per_atu_si, 

103 force=u.hartree_per_bohr_si, 

104 temperature=u.kelvin_si, 

105 pressure=u.pascal_si, 

106 charge=u.e_si, # multiple of electron charge (1.0 is a proton) 

107 dipole=u.debye_si, 

108 electric_field=u.volt_per_centimeter_si, 

109) 

110 

111UNITSETS["micro"] = dict( 

112 mass=u.picogram_si, 

113 distance=u.micrometer_si, 

114 time=u.microsecond_si, 

115 energy=u.picogram_micrometersq_per_microsecondsq_si, 

116 velocity=u.micrometer_per_microsecond_si, 

117 force=u.picogram_micrometer_per_microsecondsq_si, 

118 torque=u.picogram_micrometersq_per_microsecondsq_si, 

119 temperature=u.kelvin_si, 

120 pressure=u.picogram_per_micrometer_microsecondsq_si, 

121 dynamic_viscosity=u.picogram_per_micrometer_microsecond_si, 

122 charge=u.picocoulomb_si, # (1.6021765e-7 is a proton), 

123 dipole=u.picocoulomb_micrometer_si, 

124 electric_field=u.volt_per_micrometer_si, 

125 density=u.picogram_si / (u.micrometer_si) ** DIM, 

126) 

127 

128UNITSETS["nano"] = dict( 

129 mass=u.attogram_si, 

130 distance=u.nanometer_si, 

131 time=u.nanosecond_si, 

132 energy=u.attogram_nanometersq_per_nanosecondsq_si, 

133 velocity=u.nanometer_per_nanosecond_si, 

134 force=u.attogram_nanometer_per_nanosecondsq_si, 

135 torque=u.attogram_nanometersq_per_nanosecondsq_si, 

136 temperature=u.kelvin_si, 

137 pressure=u.attogram_per_nanometer_nanosecondsq_si, 

138 dynamic_viscosity=u.attogram_per_nanometer_nanosecond_si, 

139 charge=u.e_si, # multiple of electron charge (1.0 is a proton) 

140 dipole=u.electron_nanometer_si, 

141 electric_field=u.volt_si / u.nanometer_si, 

142 density=u.attogram_si / u.nanometer_si ** DIM, 

143) 

144 

145 

146def convert(value, quantity, fromunits, tounits): 

147 """Convert units between LAMMPS and ASE. 

148 

149 :param value: converted value 

150 :param quantity: mass, distance, time, energy, velocity, force, torque, 

151 temperature, pressure, dynamic_viscosity, charge, dipole, 

152 electric_field or density 

153 :param fromunits: ASE, metal, real or other (see lammps docs). 

154 :param tounits: ASE, metal, real or other 

155 :returns: converted value 

156 :rtype: 

157 """ 

158 return UNITSETS[fromunits][quantity] / UNITSETS[tounits][quantity] * value