NAM_CH_SOLVERn

NAM_CH_SOLVERn content

Fortran name	Fortran type	Default value
CSOLVER	CHARACTER(LEN=32)	‘EXQSSA’
NSSA	INTEGER	0
NSSAINDEX	ARRAY(INTEGER)	1000*0
XRTOL	REAL	0.001
XATOL	REAL	0.1
NRELAB	INTEGER	2
NPED	INTEGER	1
NMAXORD	INTEGER	5
LPETZLD	LOGICAL	.TRUE.
CMETHOD	CHARACTER(LEN=1)	N
CNORM	CHARACTER(LEN=1)	A
NTRACE	INTEGER	0
XALPHA	REAL	0.5
XSLOW	REAL	100.0
XFAST	REAL	0.1
NQSSAITER	INTEGER	1
XDTMIN	REAL	0.1
XDTMAX	REAL	600.0
XDTFIRST	REAL	10.0

• CSOLVER : type of numerical method used to resolve the ode system of coupling differential equations for chemistry (chemistry solver). for the description of each method, see the associated ch_routine. rosenbrock’method are gouped in mode_RBK90_Integrator routine. possible values are:

  • ‘SIS’

  • ‘LINSSA’

  • ‘CRANCK’

  • ‘QSSA’

  • ‘EXQSSA’

  • ‘ROS1’

  • ‘ROS2’

  • ‘ROS3’

  • ‘ROS4’

  • ‘RODAS3’

  • ‘RODAS4’

  • ‘ROSENBROCK’: default method ROS1 with ROSENBROCK

• NSSA : number of variables to be treated as “steady state”.

• NSSAINDEX : index set of steady state variables.

• XRTOL : relative tolerance for SVODE and D02EAF, D02EBF, D02NBF methods.

• XATOL : absolute tolerance for SVODE and D02NBF.

• NRELAB : choose relative error for NAG’s D02EBF solver:

  • 1 : for correct decimal places

  • 2 : for correct significant digits

  • 0 : for a mixture

• NPED : calculation parameter of the Jacobian matric for SVODE and NAG’s D02EBF/D02NBF solvers:

  • 1 : for analytical Jacobian (using subroutine CH_JAC)

  • 0 : for numerical Jacobian

• NMAXORD : maximum order for the BDF method (0<NMAXORD<=5) for NAG’s D02NBF solver.

• LPETZLD : switch to activate Petzold local error test (recommended) for NAG’s D02NBF solver.

• CMETHOD : method to use non-linear system for NAG’s D02NBF solver.

  • ‘N’ or ‘D’ : modified Newton iteration

  • ‘F’ : functional iteration

• CNORM : type of norm to be used for NAG’s D02NBF solver.

  • ‘A’ or ‘D’ : averaged L2 norm

  • ‘M’ : maximum norm

• NTRACE : level of output from D02NBF solver:

  • -1 : no output

  • 0 : only warnings are printed

  • >= 1 : details on Jacobian entries, nonlinear iteration and time integration are given

• XALPHA : the Cranck-Nicholson parameter (0,1).

• XSLOW : slow species, lifetime > XSLOW * timestep for EXQSSA and QSSA methods.

• XFAST : fast species, lifetime < XFAST * timestep for EXQSSA and QSSA methods.

• NQSSAITER : number of iterations in QSSA method.

• XDTMIN : minimal allowed timestep for EXQSSA.

• XDTMAX : maximal allowed timestep for EXQSSA.

• XDTFIRST : timestep for first integration step of EXQSSA.