The options that are required if Options is set to "Specified" and LINMETH is set to Chi MD are on the Chi MD Variables of the NWT: Newton Solver pane of the the MODFLOW Packages and Programs dialog box under Solvers.
IACL is a flag for the acceleration method:
NORDER is a flag for the scheme of ordering the unknowns: 0= original ordering;
LEVEL is the level of fill for incomplete LU factorization.
NORTH is the number of orthogonalization for the ORTHOMIN acceleration scheme. A number between 4 and 10 is appropriate. Small values require less storage but more iterations may be required. This number should equal 2 for the other acceleration methods.
IREDSYS is a flag for reduced system preconditioning: =1 apply reduced system preconditioning; = 0 do not apply reduced system preconditioning.
RRCTOLS is the residual reduction-convergence criteria.
IDROPTOL is a flag for using drop tolerance in the preconditioning.
EPSRN is the drop tolerance for preconditioning.
HCLOSEXMD is the head closure criteria for inner (linear) iterations.
MXITERXMD is the maximum number of iterations for the linear solution.
