Thermodynamics operators
21 operators in the thermodynamics category of the live registry. Compose them in a contract or call POST /api/zeq/compute — KO42 is always on, plus up to three more per call.
How it computes: dedicated closed-form solver solveTD — real equations over CODATA-2018 constants; where an operator needs a series/matrix/field a scalar cannot express, it refuses honestly. See the solvers.
| Operator | Description | Equation |
|---|---|---|
FEP0 | Helmholtz free energy from the partition function: F = -k_BT ln Z. | ∫(∂log f/∂θ)² f dx |
MAXREL | Maxwell relations: the four thermodynamic identities from the equality of mixed second partials of the potentials, e.g. (∂S/∂V)_T = (∂P/∂T)_V. | (∂S/∂V)_T = (∂P/∂T)_V |
RTEO9 | Heat equation with volumetric source term governing temperature evolution by diffusion. | \frac{\partial T}{\partial t} = \alpha\nabla^2 T + \frac{q}{\rho c_p} |
TH1 | First law of thermodynamics: internal energy change equals heat added minus work done. | \Delta U = Q - W |
TH10 | Thermal pressure coefficient relating pressure change to temperature change at constant volume. | \left(\frac{\partial P}{\partial T}\right)_V = \frac{\alpha}{\kappa_T} |
TH11 | Enthalpy defined as internal energy plus pressure-volume product. | H = U + PV |
TH12 | Chemical potential: partial derivative of Gibbs free energy with respect to particle number. | \mu = \left(\frac{\partial G}{\partial N}\right)_{T,P} |
TH13 | Fundamental thermodynamic relation combining first and second laws with chemical work. | dU = TdS - PdV + \mu dN |
TH14 | Heat capacity at constant volume as the partial derivative of internal energy with respect to temperature. | C_V = \left(\frac{\partial U}{\partial T}\right)_V |
TH15 | Thermal conductivity defined through Fourier's law of heat conduction. | \kappa = \frac{dQ/dt}{A \cdot dT/dx} |
TH2 | Ideal gas law relating pressure, volume, amount, and temperature of an ideal gas. | PV = nRT |
TH3 | Second law of thermodynamics: entropy of an isolated system never decreases. | \Delta S \geq \frac{Q}{T} |
TH4 | Carnot efficiency: maximum possible efficiency of a heat engine between two temperatures. | \eta = 1 - \frac{T_C}{T_H} |
TH5 | Boltzmann entropy: S = k_B ln(Omega), connecting thermodynamic entropy to microstates. | S = k_B \ln \Omega |
TH6 | Helmholtz free energy: thermodynamic potential for systems at constant temperature and volume. | F = U - TS |
TH7 | Gibbs free energy: thermodynamic potential for systems at constant temperature and pressure. | G = H - TS |
TH8 | Mayer relation: difference between heat capacities at constant pressure and constant volume. | C_p - C_v = nR |
TH9 | Adiabatic process law: pressure times volume to the gamma power is constant. | PV^\gamma = \text{const} |
TTHIRD | Third law of thermodynamics: the entropy of a perfect crystal approaches zero as the absolute temperature approaches zero, S → 0 as T → 0. | S → 0 as T → 0 |
TZERO | Zeroth law of thermodynamics: if two systems are each in thermal equilibrium with a third, they are in equilibrium with each other — the transitivity that makes temperature well-defined. | A~C ∧ B~C ⟹ A~B |
VDW1 | Van der Waals equation of state for a real gas: (P + a·n²/V²)(V − n·b) = nRT — corrects the ideal-gas law for molecular attraction (a) and finite molecular volume (b). | (P + a n²/V²)(V − nb) = nRT |
Compute one — a real call
Ask the operator which inputs it needs (the honesty contract refuses empty inputs rather than inventing them):
curl -sS -X POST https://zeqsdk.com/api/zeq/operator-spec \
-H "Content-Type: application/json" \
-d '{"operator":"FEP0"}'
See also
- The solvers — the coverage map and the ODE fallback
- The honesty contract — compute, ask, or refuse
- All operator categories