Add support for atomic units (#158)

Author: GardevoirX

docs/src/torch/reference/misc.rst

@@ -28,13 +28,15 @@ one of the registered unit.
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
 |   **energy**   | ``eV``, ``meV``, ``Hartree``, ``kcal/mol``, ``kJ/mol``, ``Joule`` (``J``), ``Rydberg`` (``Ry``)                                                      |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
-|   **force**    | ``eV/Angstrom`` (``eV/A``, ``eV/Angstrom``)                                                                                                          |
+|   **force**    | ``eV/Angstrom`` (``eV/A``), ``Hartree/Bohr``                                                                                                         |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
-|   **pressure** | ``eV/Angstrom^3`` (``eV/A^3``, ``eV/Angstrom^3``)                                                                                                    |
+|   **pressure** | ``eV/Angstrom^3`` (``eV/A^3``)                                                                                                                       |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
-|   **momentum** | ``u*A/fs``, ``u*A/ps``, ``(eV*u)^(1/2)``, ``kg*m/s``                                                                                                 |
+|   **momentum** | ``u*A/fs``, ``u*A/ps``, ``(eV*u)^(1/2)``, ``kg*m/s``, ``hbar/Bohr``                                                                                  |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
-|    **mass**    | ``u`` (``u``, ``Dalton``), ``kg`` (``kg``, ``kilogram``), ``g`` (``g``, ``gram``)                                                                    |
+|    **mass**    | ``u`` (``Dalton``), ``kg`` (``kilogram``), ``g`` (``gram``), ``electron_mass`` (``m_e``)                                                             |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
-|   **velocity** | ``nm/fs``, ``A/fs``, ``m/s``, ``nm/ps``                                                                                                              |
+|   **velocity** | ``nm/fs``, ``A/fs``, ``m/s``, ``nm/ps``, ``Bohr*Hartree/hbar``                                                                                       |
++----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+
+|   **charge**   | ``e``, ``Coulomb`` (``C``)                                                                                                                           |
 +----------------+------------------------------------------------------------------------------------------------------------------------------------------------------+

metatomic-torch/src/model.cpp

@@ -1108,6 +1108,7 @@ static std::map<std::string, Quantity> KNOWN_QUANTITIES = {
     }}},
     {"force", Quantity{/* name */ "force", /* baseline */ "eV/Angstrom", {
         {"eV/Angstrom", 1.0},
+        {"Hartree/Bohr", 0.019446904}
     }, {
         // alternative names
         {"eV/A", "eV/Angstrom"},
@@ -1123,25 +1124,29 @@ static std::map<std::string, Quantity> KNOWN_QUANTITIES = {
         {"u*A/ps", 1000.0},
         {"(eV*u)^(1/2)", 10.1805057179},
         {"kg*m/s", 1.6605390666e-22},
+        {"hbar/Bohr", 83.32476},
     }, {
         // alternative names
     }}},
     {"mass", Quantity{/* name */ "mass", /* baseline */ "u ", {
         {"u", 1.0},
         {"kilogram", 1.66053906892e-27},
         {"gram", 1.66053906892e-24},
+        {"electron_mass", 1822.8885},
     }, {
         // alternative names
         {"Dalton", "u"},
         {"kg", "kilogram"},
         {"g", "gram"},
+        {"electron_mass", "m_e"},
     }}},
     {"velocity", Quantity{/* name */ "velocity", /* baseline */ "nm/fs", {
         {"nm/fs", 1.0},
         {"A/fs", 1e1},
         {"m/s", 1e6},
         {"nm/ps", 1e3},
         {"(eV/u)^(1/2)", 101.80506},
+        {"Bohr*Hartree/hbar", 0.45710289},
     }, {
         // alternative names
     }}},