Constraint Parameters

Instead of introducing spring between the connecting particles, we may introduce constraints for each connection. This approach is called ``bead-rod'' model.

	constraints : list in the following format;
	(define constraints '(
	 ; system parameters
	 1.0e-6    ; 1) tolerance
	 "NITSOL"  ; 2) scheme for solving nonlinear equations
	             ;  "linear" for iterative scheme in linear approximation
	             ;  "NITSOL" for Newton-GMRES scheme by NITSOL library
	 ; the following is for each constraint
	 (         ; 3) constraint type 1
	  5.0      ; 3-1) distance [nm]
	  (        ; 3-2) list of particle-pairs
	   (0 1)
	   (1 2)
	   (2 3)
	 ))
	 (         ; 4) constraint type 2
	  10.0     ; 4-1) distance [nm]
	  (        ; 4-2) list of particle-pairs
	   (3 4)
	   (4 5)
	 ))
	))