|----------------------------------------------------------------------

        | Run-time Perple_X 6.9.1 options:

        | For option documentation refer to: www.perplex.ethz.ch/perplex_options.html

        |-------------------------------------------------------------
        | NOTE: to avoid accidental option settings create personalized and/or
        | problem specific option files (e.g., my_problem_option.dat) that specify 
        | only those options that have non-default values. 
        |-------------------------------------------------------------

        | Comments must be preceeded by the "|" character.

        | 0) All keywords accept the default value, in which case the keyword is assigned its default attributes.
        | 1) Keywords and values are case sensitive.
        | 2) Keywords that take the value T (true) or F (false) are always binary.
        | 3) Keywords that take the value on, always may take the value off, but may accept other values as indicated below.
        | 4) Default keyword values are indicated in square brackets in the comment following each keyword.

        | To change the value of an option from "default" the word "default" 
        | must be replaced with the desired value. For example, to change the 
        | x-grid resolution from its default values [40 and 40] to 20 and 60, the 
        | keyword must be changed from 

        | x_nodes default ...

        |   to 

        | x_nodes 20 60 ...

|----------------------------------------------------------------------

| 691+ options, these are options that did not exist in earlier versions:

|                         setting intermediate_savrpc and intermediate_savdyn to T is the
|                         method of first resort to improve on calculations with VERTEX/MEEMUM
|                         that result in rough phase boundaries or blotchy patches of failed
|                         optimizations.

dynamic_LP_start          default | [warm] hot, cold, warm. 
GFSM                      default | [F] allow GFSM/disable saturated-phase constraints
intermediate_savrpc       default | [F] save intermediate compositions during dynamic optiomization
intermediate_savdyn       default | [F] save intermediate dynamic compositions as auto-refine static compositions
logarithmic_X             default | [F] VERTEX/MEEMUM only, replace saturated phase compositional variable X with log10(X)
LP_max_it                 default | [500] max number of iterations for a single LP optimization
MINFRC_diff_increment     default | [1d-7] finite difference increment used during NLP when analytical derivatives are not available
MINFXC_solver             default | [0] -1 -> 3, controls use of the specis/mifxc o/d solvers
optimization_max_it       default | [40] maximum number of sucessive LP optimizations
optimization_precision    default | [1d-3 energy unit] absolute precision for succesive LP optimization
phi_d                     default | [0.36] 0-1, disaggregation porosity used by fluid_shear_modulus
replicate_threshold       default | [1d-2] effective initial resolution for auto-refine stage , nopt(35) 
rep_dynamic_threshold     default | [1d-3] threshold for saving compositions during dynamic optimization, nopt(37) 
re-refine                 default | [F] allows iterative auto-refinement
scatter-increment         default | [1d-3] scatter increment for scatter-points option
scatter-points            default | [T] generate additional compositions scattered about refinement points
fluid_shear_modulus       default | [T] wetting model for aggregate shear modulus
speciation_precision      default | [1d-5] precision for non-GFSM fluid speciation calculations
timing                    default | [T] output CPU time statistics
warn_interactive          default | [F] overrides interactive y/n warnings by setting the y answer
warn_no_limit             default | [F] overrides use of counters to limit the number of warning messages

|----------------------------------------------------------------------

| 690- options that remain functional in 691+:

1d_path                   default | [40 150] exploratory and autorefine (grid parameters keyword group)
absolute                  default | [F] WERAMI - output absolute component amounts
Anderson-Gruneisen        default | [F] Anderson-Gruneisen parameter correction for polythermal Murnaghan and Birch-Murnaghan
approx_alpha              default | [T] use approximation exp(x) ~ 1+x to evaluate expansivity effect on volume
aq_bad_results            default | [error]* 101 102 103 or ignore => response to suspect lagged speciation results. *defaults to 101 for fractionation problems
aq_output                 default | [T] output back-calculated solute chemistry when electrolyte data is available
aq_oxide_components       default | [F] accomodate oxide components in aqueous speciation calculations
aq_species                default | [20] maximum number of solute species output (ranked by concentration) for back-calculated results
aq_lagged_iterations      default | [0] number of internal iterations for lagged speciation.
aq_lagged_speciation      default | [F] do lagged solute chemistry when electrolyte data is available
aq_solute_composition     default | [m] y => mole fractions, m => molality
aq_solvent_composition    default | [y] y => mole fractions, m => molality
aq_solvent_solvus         default | [T] allow solvent phase separation without aq_bad_results error trigger
aq_vapor_epsilon          default | [1.] dielectric constant threshold used to identify vapor
auto_exclude              default | [T] exclude phases or species with no associated P-V EoS
auto_refine               default | [auto] auto, manual, or off (auto_refine keyword group)
auto_refine_file          default | [T] echo exploratory stage auto-refine data to my_project_auto_refine.txt
bad_number                default | [NaN] any number or NaN (not-a-number)
bounds                    default | [VRH] VRH or HS; Voigt-Reuss-Hill or Hashin-Shtrikman, see vrh/hs_averaging
closed_c_space            default | [T] T => closed composition space for gridded minimization 
composition_constant      default | [F] allow constants in composition expressions
composition_phase         default | [mol] mol or wt (mass) phase compositions in WERAMI output
composition_system        default | [wt] mol or wt; system composition in WERAMI mode 2-4 output
console_messages          default | [on] off => suppresses most console messages (warnings, errors, etc)
cumulative                default | [F] WERAMI, computational mode 3, property choice #36 only!- cumulative component amounts (for fractionation problems)
dependent_potentials      default | [on] off => compute dependent thermodynamic potentials (usually chemical potentials)
efficiency                default | [3] 1->5, only relevant for CONVEX
explicit_bulk_modulus     default | [T] T => use explicit function for bulk modulii if available
fancy_cumulative_modes    default | [F] T => order cumulative modes to account for univariant reactions (WERAMI, mode 3, property 25)
fd_expansion_factor       default | [2] nth order finite difference increment is increased by fd_expansion_factor^(n-1)
finite_difference_p       default | [1d4 1d-2] threshold and fraction for 1st order finite difference increment on pressure
fractionation_hi_limit    default | [0.] 0-1, upper fractionation threshold, mass fraction
fractionation_lo_limit    default | [0.] 0-1, lower fractionation threshold, mass fraction
grid_levels               default | [1 4] exploratory and auto-refine (grid parameters keyword group)
hard_limits               default | [off] on or off; on => strictly impose compositional limits specified in solution model
hybrid_EoS_H2O            default | [4] 0-2, 4-5 => 0 - MRK, 1 HSMRK, 2 - CORK, 4 - PSEoS, 5 - Haar, 6 - Zhang & Duan 05, 7 - Zhang & Duan 09
hybrid_EoS_CO2            default | [4] 0-4 => 0 - MRK, 1 HSMRK, 2 - CORK, 3- Bottinga, 4 - PSEoS, 6 - Zhang & Duan 05, 7 - Zhang & Duan 09
hybrid_EoS_CH4            default | [1] 0-1  => 0 - MRK, 1 HSMRK, 7 - Zhang & Duan 09
increment                 default | [0.1 0.025] >0, < 1, fractional independent variable increments [exploratory and auto-refine], only relevant for CONVEX
initial_resolution        default | VERTEX/MEEMUM [1/5]. CONVEX: Schreinemakers [1/16 1/48], composition and mixed variable diagrams [1/16 1/160].
interim_results           default | [auto] auto, off or on
interpolation             default | [on 2] value 1: on or off [on]; value 2, 1->99 [2]; only relevant for WERAMI
linear_model              default | [on] on or off, relevant for 2d gridded minimization
logarithmic_p             default | [F], VERTEX/MEEMUM only, replace pressure variable with log10(pressure)
melt_is_fluid             default | [T] identify melt (liquid) as fluid in MEEMUM/WERAMI output
non_linear_switch         default | VERTEX/MEEMUM [F], CONVEX [T], toggles whether nonlinear subdivision uses initial_resolution
null_phase                default | [F] include null phases in convexhull optimization with mobile components
option_list_files         default | [F] T => echo run-time options to my_project_PROGRAM_options.txt
output_iteration_details  default | [F] T => output intermediate adaptive optimization information
output_iteration_G        default | [F] T => print iteration G to monitor convergence during optimization
pause_on_error            default | [T] T => wait for user response after errors
pc_perturbation           default | [5d-3] pseudo-compound composition perturbation; only relevant for CONVEX
poisson_ratio             default | [on 0.35] value 1: on, off or all; value 2: 0->0.5; controls use of poisson ratio estimates for shear moduli
poisson_test              default | [F] T => use poisson ratio to check for valid results
proportions               default | [vol] vol, wt, or mol; volume, weight (mass), or molar phase proportions
pseudocompound_file       default | [F] echo static pseudocompound compositions to my_project_pseudocompound_list.txt
reaction_format           default | [minimum] minimum, full, stoich, S+V, or everything
reaction_list             default | [off] on or off
refinement_points         default | [auto] or an integer > 0, max number of metastable refinement points retained during adaptive minimization
refinement_switch         default | [F] allow metastable refinement points for stable solutions
refine_endmembers         default | [F] accept endmember compositions as refinement points
reject_negative_sites     default | [T] reject compositions with negative site populations
sample_on_grid            default | [T] F => WERAMI (mode 2) samples on the computational grid used by VERTEX
seismic_output            default | [some] all, some, none
seismic_data_file         default | [F] summarize options used for endmembers and solutions
short_print               default | [on] suppress output of equilibrium coordinates to the print file, only relevant for CONVEX
solution_names            default | [mod] mod, abb or ful; use the model, abbreviation, or full name for solution models for output
solvus_tolerance          default | [auto] auto or 0->1, should be > initial_resolution/auto_refine_factor
solvus_tolerance_II       default | [0.2] 0->1 
speciation_max_it         default | [100] maximum number of iterations permitted in iterative calculations
species_output            default | [T] T => output phase speciation in MEEMUM/WERAMI mode 1 output
species_Gibbs_energies    default | [F] T => output species Gibbs energies in MEEMUM/WERAMI mode 1 output
spreadsheet               default | [F] T => include independent variable values in WERAMI tab output files 
stretch_factor            default | [2d-3] >0, <1; controls degree of assymmetry for non-linear subdivision (1 => linear, 0 => logarithmic)
subdivision_override      default | [off] off, linear, or stretch; overrides subdivision mode specified in solution models
Tisza_test                default | [T] F => use Tisza's criterion to identify invalid properties
T_melt                    default | [873.] melt solution model endmember temperature (K) cut off
T_stop                    default | [0.] equilibration temperature (K) cut off
variance                  default | [1 99] exploratory and auto-refine; maximum variance of traced equilibria; only relevant for CONVEX
vrh/hs_weighting          default | [0.5] 0->1, weighting factor for the stiff average in VRH/HS averaging (see bounds)
warning_ver637            default | [T] F -> warn and cease interpolation in WERAMI when immiscible solutions are present
x_nodes                   default | [10 40] exploratory and auto-refine (grid parameters keyword group), lowest-level x grid resolution 
y_nodes                   default | [10 40] exploratory and auto-refine (grid parameters keyword group), lowest-level y grid resolution
zero_mode                 default | [1e-6] 0->1, threshold below which the molar mode of a phase is set to 0; defaults to zero for fractionation calculations
