Control Options

YREC is generally called with two namelist arguments: the “control” namelist, or nml1; and the “physics” namelist, or nml2. This page is a reference that will document various current and deprecated possible values in the namelist files.

Control (.nml1)

Run parameters & Kind cards

YREC runs are separated into a number of “phases”, referred to as KINDRN’s. After completion of a KINDRN, execution will move onto the next KINDRN. This functionality is designed so that different phases of rescaling, evolving, or rescale & evolving, can be done in a single stellar evolution model run.

One NUMRUN should be defined, with the number of total KINDRN’s. Replace i with 1,2,3… etc, for the behavior of each step:

Parameter	Description
NUMRUN	Each YREC run can rescale a model, evolve a model, or do both (pre-MS only). This indicates the total number of such steps requested, N.
KINDRN(i)	1 = evolve 2= rescale (zero timestep, MS, or CHeB); 3 = rescale and evolve (pre-MS, where there is no zero timestep solution). This needs to be defined for each KINDRN in sequence.
LFIRST(i)	.TRUE. = use stored starting model (FFIRST). .FALSE. = use result of prior KINDRN step
RSCLM(i)	If positive, rescale to this mass (\(M_\odot\)).
RSCLCM(i)	If positive, rescale to this core mass (CHeB only).
RSCLX(i)	If positive, rescale to this hydrogen.
RSCLZ(i)	If positive, rescale to this metallicity.
NMODLS(i)	Stop after this number of models. An initial rescaling with 2 models is recommended, followed by an evolve run.
XENV0A(i)	Envelope abundance label.
ZENV0A(i)	Envelope abundance label.
CMIXLA(i)	Rescale to this mixing length (or use for the run).
LSENV0A(i)	If true, adjust outer fitting point mass location to SENV0A(i).
SENV0A(i)	Log of fractional envelope fitting point mass. 1e-4 standard, 1e-7 thin.
ENDAGE(i)	Run stops if NMODLS(i) is reached or this age is reached.
END_DCEN(i)	Run stops if NMODLS(i) is reached or this central deuterium is reached (D Birthline, start: 2.75d-5, D Birthline, end: 2.75d-7).
END_XCEN(i)	Run stops if NMODLS(i) is reached or this central hydrogen is reached (ZAMS: 0.714620, TAMS: 0.0001).
END_YCEN(i)	Run stops if NMODLS(i) is reached or this central helium is reached (ZAHB: 0.9700, TAHB: 0.0001).

File Location Specifiers

Environment Variables

YREC supports substitution of path components within the CONTROL namelist files via a set of placeholders. The placeholders may be used as a prefix in path values found in the CONTROL namelist to allow a generalized file that will function in a variefy of contexts without requiring edits, e.g., if the location of the inputs tree or starting model changes relative to the working directory.

Supported environment variables are: YREC_INPUT YREC_START YREC_OUTPUT

Those names, enclosed in curly braces ({}) will be replaced by the value of the corresponding environment variable as defined within the YREC execution environment. Especially for the YREC_INPUT and YREC_START values, setting an absolute path can provide the greatest flexibility in locating input files across multiple potential execution locations.

If any of those variables are not defined in the execution environment, a default value for the path prefix that each represents will be used instead.

Placeholder	Default value
{YREC_INPUT}	"../../input"
{YREC_START}	"../../input/models"
{YREC_OUTPUT}	"output" (within the working directory where yrec is invoked)

Example:

In the CONTROL namelist, FOPALE06 = "{YREC_INPUT}/eos/opal2006/EOSOPAL06Z0.016492"

If the environment variable is not defined, the default prefix will be used and the value becomes
FOPALE06 = "../../input/eos/opal2006/EOSOPAL06Z0.016492" at runtime.

Whereas if one sets the environment variable,

export YREC_INPUT=/path/to/input/tree

the value will expand to
FOPALE06 = "/path/to/input/tree/eos/opal2006/EOSOPAL06Z0.016492" at runtime.

Input files

Opacity tables & options:

Parameter	Description
LALEX06	If .TRUE., use Ferguson+2005 molecular opacities (recommended).
FALEX06	Molecular opacity table path.
LOPAL95	If .TRUE., use atomic opacities in the OP/OPAL format (recommended).
ZOPAL951	Generate a surface mixture table with this Z. Speeds up models without diffusion.
FLIV95	Atomic opacity table path.
LPUREZ
FPUREZ	Pure Y/Z opacity table path.
FcondOpacP	Conductive opacity table path.

Equation of state tables:

Parameter	Description
FOPALE06	OPAL 2006 EOS table path.
FATM	Model atmosphere look-up table for Kurucz and Kurucz/Castelli.
FALLARD	Allard model atmosphere look-up table (solar Z only).
FSCVH	SCZ EoS table for X.
FSCVHE	SCZ EOS table for Y.
FSCVZ	SCZ EoS table for Z (generated from YREC EOS, needed for consistency)
FFERMI	Fermi integral tables for partial degeneracy.

Starting model:

Parameter	Description
FFIRST	Starting model file.

Output

The starting and last models include only abundances and structure variables. These options allow snapshots to be generated with more information.

Output options:

Parameter	Description
LSTORE	If .TRUE., store model structures at specified points to the .store file.
LSTCH	If .TRUE., writes out interior, envelope, and atmosphere output (as controlled by LSTATM and LSTENV) in a single, consistent format (recommended). The default is different formats for each.
LSTATM	If .TRUE., append an atmosphere to the stored model file.
LSTENV	If .TRUE., envelope to the stored model file. If LSTENV and LSTATM = .FALSE., no information is output beyond the fitting point.
LSTMOD	Set the same as LSTORE. May be redundant.
LSTPHYS	If .TRUE., output microphysics (e.g. epsilon, kappa) to .store file.
LSTROT	If .TRUE., append rotation data to .store file.
NPRTMOD	Output detailed model structures every NPRTMOD models. Negative = skip intermediate structures (can still output the final model if LSTPCH=.TRUE.
NPRTPT	Output details for every NPRTPT points (if 1000 points and NPRTPT=10, 100 lines are output).
LSTPCH	If .TRUE., output details of the final model to the .store file.
LTRACK	If .TRUE., global properties are output to the .track file. This should almost always be on.
ITRVER	Toggle for different track file formats. 0 (one line per model) strongly recommended.
LRWSH	If .TRUE., the .short. file retains only the details from the last model. This minimizes output file size.
LCORR	If .TRUE., output verbose details on model convergence to .short.
LPULSE	If .TRUE., generate pulsation output. LSTATM AND LSTENV are needed to get data for those regions (needed if LPULSE is .TRUE.)
IPVER	Format for pulsation output.
LSTPCH	If .TRUE., output details of the final model to the .store file.
LSTPCH	If .TRUE., output details of the final model to the .store file.

Output files:

Parameter	Description
FLAST	The last converged model is stored here.
FSTOR	Model snapshots during the run are stored here.
FTRACK	Global variables as a function of time are stored here.
FSHORT	Details about the numerics of the model run are stored here.
FPMOD	Pulsation output for the interior model.
FPENV	Pulsation output for the envelope model.
FPATM	Pulsation output for the atmosphere model.

Legacy output files:

Parameter	Description
FMODPT	No longer used.
FSNU	No longer used (formally, output if LSNU = .TRUE.).
FSCOMP	No longer used (light elements vs. time, now included in .track file)

Mixtures

In addition to X, Y, & Z, YREC stores light elements (D He3 Li6 Li7 Be9) and CNO isotopes (C12 C13 N14 O16 O18) B10 B11 N15 O17 to be added.

These options adjust their relative abundances. It is recommended to tie these to preset mixtures used in opacity tables. This should be done at the start of a model run, and only work if LFIRST = .TRUE. Option to adjust the CNO mixture to be consistent with the mixture used in the opacity tables.

Parameter	Description
ISETMIX	0 = do not adjust, 1 = use specified mixture (AMIX), 2 = custom mixture (variables at the end of the namelist)
AMIX	current implemented solar mixtures are GS98, AAG21, M22P, and M22M.

Option to adjust the D/He3/Li6/Li7/Be9 abundances and the CNO isotope ratios to be consistent with a specified solar reference

Parameter	Description
ISETISO	0 = do not adjust, 1 = use specified mixture (AISO), 2 = custom mixture (variables at the end of the namelist)
AISO	L21: Lodders 2021 is currently the only supported mixture, for a different one use the custom option.

Custom mixture controls:

CNO enabled if ISETMIX = 2, Light elements if ISETISO=2

Total CNO (isotope ratios controlled with ISETISO):

Parameter	Description
FRAC_C	Mass fraction of metals in the form of carbon. GS98: 0.172148
FRAC_N	Mass fraction of metals in the form of nitrogen. GS98: 0.050426
FRAC_O	Mass fraction of metals in the form of oxygen. GS98: 0.468195

Isotope ratios and light elements:

Parameter	Description
R12_13	C12/C13 ratio, L21 mix (88.26 L25)
R14_15	N14/N15 ratio, L21 mix (412.3 L25) - placeholder,N15 not currently used
R16_17	O16/O17 ratio, L21 mix (2644 L25)- placeholder,O17 not currently used
R16_18	O16/O18 ratio, L21 mix (468.2 L25)

Light element abundances:

Parameter	Description
XH2_INI	Initial D mass fraction, L21 mix (2.780e-5 L25)
XHE3_INI	Initial He3 mass fraction, L21 mix (3.443e-5 L25)
XLI6_INI	Initial Li6 mass fraction, L21 mix (7.830e-10 L25)
XLI7_INI	Initial Li7 mass fraction, L21 mix (1.112e-8 L25)
XBE9_INI	Initial Be9 mass fraction, L21 mix (1.810e-10 L25)
XB10_INI	Initial B10 mass fraction, L21 mix (1.099e-9 L25) - placeholder, not currently used
XB11_INI	Initial B11 mass fraction, L21 mix (4.885e-9 L25) - placeholder, not currently used

Calibration

Parameter	Description
LCALS	Toggle to auto-calibrate solar Y and alpha to match the solar R and L at the age of the Sun.
LCALSOLZX	Enforce correct Z/X (CALSOLZX) for mixture. If this is false Z is held constant in the calibration loop.
CALSOLZX	Target solar Z/X. (0.02292 is GS98)
TOLL	Tolerance target for L in the calibration routines.
TOLR	Tolerance target for R in the calibration routines.
CALSOLAGE	Tolerance solar age in the calibration routines.