Thermodynamic observables ------------------------- ### Objective This module defines a set of thermodynamic observables commonly output by molecular simulation programs. ### Module name and version The name of this module is `thermodynamics`. The module version is 1.0.0. ### Observables Thermodynamic observables are stored in the `observables` group for global properties or in `observables/` for subsystems, similarly to the `particles` group. The groups have the following contents: observables \-- +-- dimension: Integer[] \-- particle_number \-- (pressure) \-- (temperature) \-- (density) \-- ... `dimension` : A scalar attribute of `Integer` type that gives the dimension of the space embedding the subsystem. `particle_number` : The number of particles in the subsystem stored as scalar H5MD element of `Integer` datatype. The following H5MD elements are optional, of scalar character, and use the `Float` datatype. `pressure` : The pressure of the subsystem. `temperature` : The (instantaneous) temperature of the subsystem as inferred from the kinetic energy. `density` : The number density of the subsystem stored as `Float` or `Integer` datatype. `potential_energy` : The potential energy of the subsystem. `kinetic_energy` : The kinetic energy of the subsystem. `internal_energy` : The internal energy of the subsystem, typically the sum of potential and kinetic energy. `enthalpy` : The enthalpy of the subsystem. The latter 4 quantities are stored as per-particle averages. The corresponding extensive quantities (scaling linearly with the system size) are obtained by multiplication with the number of particles. Per-volume averages follow by multiplication with the number density if present.