The following physical constants are used in PC1D calculations:
| Elementary charge, q | 1.6021773E-19 C |
| Thermal voltage at 300 K, kT/q | 0.025851483 V |
| Photon energy factor, hc | 1239.8424 eV-nm |
| Permittivity of free space, eo | 8.8541878E-14 F/cm |
| Kelvin-Celsius offset | 273.15 K |
| Circle geometry constant, p | 3.14159265359 |
The following program constants are constraints in this version of PC1D:
| Maximum Elements | 500 |
| Maximum Time Steps | 200 |
| Maximum Wavelengths | 200 |
| Maximum Regions | 5 |
| Maximum Batch Columns | 30 |