# surfacereactions

Fortran module: `surfacereactions`

## Parameters

User-configurable parameters (can be set via `param_dict`):

| Parameter | Type | Default | Description |
|-----------|------|---------|-------------|
| `bulklayersreciprocal` | `<class 'numpy.ndarray'>` | `0.0` |  |
| `desorptionfractionsbare` | `float64[(3421,)]` | `array(3421,)` |  |
| `desorptionfractionsfullcoverage` | `float64[(3421,)]` | `array(3421,)` |  |
| `safebulk` | `<class 'numpy.ndarray'>` | `0.0` |  |
| `safemantle` | `<class 'numpy.ndarray'>` | `0.0` |  |
| `surfacecoverage` | `<class 'numpy.ndarray'>` | `0.0` |  |
| `totalswap` | `<class 'numpy.ndarray'>` | `0.0` |  |

## Constants (Read-Only)

Fortran PARAMETER constants (compile-time values):

| Constant | Type | Value |
|----------|------|-------|
| `chemical_barrier_thickness` | `<class 'numpy.ndarray'>` | `1.4e-08` |
| `diffuse_react_competition` | `<class 'numpy.ndarray'>` | `1` |
| `dp` | `<class 'numpy.ndarray'>` | `8` |
| `gas_dust_density_ratio` | `<class 'numpy.ndarray'>` | `756764614951.0485` |
| `gas_dust_mass_ratio` | `<class 'numpy.ndarray'>` | `100.0` |
| `grain_crosssection_per_h` | `<class 'numpy.ndarray'>` | `8.1905e-22` |
| `grain_density` | `<class 'numpy.ndarray'>` | `3.0` |
| `grain_radius` | `<class 'numpy.ndarray'>` | `1e-05` |
| `grain_surfacearea_per_h` | `<class 'numpy.ndarray'>` | `3.2762e-21` |
| `grains_have_ice` | `<class 'numpy.ndarray'>` | `1` |
| `graphite_cross_section` | `<class 'numpy.ndarray'>` | `7.908e-22` |
| `graphite_e_h2` | `<class 'numpy.ndarray'>` | `520.0` |
| `graphite_e_hc` | `<class 'numpy.ndarray'>` | `30000.0` |
| `graphite_e_hp` | `<class 'numpy.ndarray'>` | `800.0` |
| `graphite_e_s` | `<class 'numpy.ndarray'>` | `260.0` |
| `graphite_mu` | `<class 'numpy.ndarray'>` | `0.005` |
| `graphite_nu_h2` | `<class 'numpy.ndarray'>` | `3000000000000.0` |
| `graphite_nu_hc` | `<class 'numpy.ndarray'>` | `13000000000000.0` |
| `h2_on_h2_binding_energy` | `<class 'numpy.ndarray'>` | `23.0` |
| `h_on_h2_binding_energy` | `<class 'numpy.ndarray'>` | `45.0` |
| `hh_vdes_prefactor` | `<class 'numpy.ndarray'>` | `2.526105662935402e+19` |
| `min_surface_abund` | `<class 'numpy.ndarray'>` | `1e-20` |
| `num_monolayers_is_surface` | `<class 'numpy.ndarray'>` | `2.0` |
| `num_sites_per_grain` | `<class 'numpy.ndarray'>` | `1884955.6446075444` |
| `silicate_cross_section` | `<class 'numpy.ndarray'>` | `8.473e-22` |
| `silicate_e_h2` | `<class 'numpy.ndarray'>` | `320.0` |
| `silicate_e_hc` | `<class 'numpy.ndarray'>` | `30000.0` |
| `silicate_e_hp` | `<class 'numpy.ndarray'>` | `450.0` |
| `silicate_e_s` | `<class 'numpy.ndarray'>` | `110.0` |
| `silicate_mu` | `<class 'numpy.ndarray'>` | `0.005` |
| `silicate_nu_h2` | `<class 'numpy.ndarray'>` | `3000000000000.0` |
| `silicate_nu_hc` | `<class 'numpy.ndarray'>` | `13000000000000.0` |
| `surface_site_density` | `<class 'numpy.ndarray'>` | `1500000000000000.0` |
| `thermal_vel` | `<class 'numpy.ndarray'>` | `14550.817143383769` |
| `tst_vdes_prefactor` | `<class 'numpy.ndarray'>` | `455331572.3602005` |
| `usecustomreducedmass` | `<class 'numpy.ndarray'>` | `1` |
| `usegarrod2011transfer` | `<class 'numpy.ndarray'>` | `1` |
| `vdiff_prefactor` | `<class 'numpy.ndarray'>` | `2.527296227517412e+22` |

## Runtime Access

Access `surfacereactions` parameters at runtime using `uclchem.advanced.GeneralSettings()`.
See [Accessing Fortran Parameters](index.html#accessing-fortran-parameters-at-runtime) on the main Fortran API page for examples.