DSNANI: A RADICAL PAIR MECHANISM PROGRAM BY JEFF CANFIELD

WHAT IS DSNANI ? WHAT CAN DSNANI DO ?

DSNANI is a C program by Jeff Canfield that calculates singlet to triplet 
(and other) yields for radical pair reactions in applied steady and 
oscillating magnetic fields. DSNANI can treat quite general spin systems, 
allowing inclusion of multiple nuclear spins, rhombic g and hyperfine (A) 
tensors (even when g,A have non-coincident principal axes), isotropic 
exchange (J), dipolar exchange (dipole interaction), anisotropic exchange 
(D,E), and nuclear Zeeman effects. 

DSNANI can also treat quite general magnetic field configurations:
it allows any orientation of steady field, it can handle multiple 
oscillating fields in any orientation with respect to the steady field 
(each field can have its own frequency, phase, orientation, and sine or 
cosine nature), some fourier components are allowed (discrete frequencies 
only), there are options to allow amplitude-modulated fields (AM), and phase 
averaging can be done. The yields can be calculated using a barrage of 
techniques: Runge-Kutta numerical integration, rotating frame treatment, 
Schrodinger (wave-function-based), mixed (wave-function-based), and Liouville 
(density-matrix-based) perturbation methods, Schrodinger formalism with 
exponential or Noyes time-dependences, and Liouville formalism that allows
ks != kt and spin relaxation (T1,T2). Some techniques are more suited to
certain cases than others but many serve as cross-checks on each other.
Certain techniques also allow time-dependent and/or powder-averaged yields
to be calculated.

DSNANI also includes routines to calculate EPR/ESR spectra for the spin
Hamiltonians used (this is a way to test DSNANI and to check input files)
and can give results comparable to published spectra and the output of 
QPOW, DISSYM, and MENO.

DSNANI also includes routines to calculate eigenvalues, eigenvectors
(in terms of singlet/triplet or up/down bases), eigenfrequencies, and 
various observables such as Fermi's Golden Rule transition intensities 
for certain oscillating field frequencies. These routines can be useful
for analyzing/understanding the yield calculations DSNANI can do. They
can also be used to check the results/test the program. 


REFERENCES:

DSNANI was used to make many of the plots shown and discussed in the 
following publications. Many of the methods used in DSNANI are outlined
in these publications as well.

(1) "A Perturbation Theory Treatment of Oscillating Magnetic Fields
in the Radical Pair Mechanism"
by J. M. Canfield, R. L. Belford, P. G. Debrunner, and K. J. Schulten
Chemical Physics, vol.182, no.1, pp.1-18, Apr.15, 1994
Chemical Physics, vol.191, no.1-3, p.347, Feb.1, 1995
http://dx.doi.org/10.1016/0301-0104(93)E0442-X
http://dx.doi.org/10.1016/0301-0104(94)00234-2

(2) "A Perturbation Treatment of Oscillating Magnetic Fields
in the Radical Pair Mechanism using the Liouville Equation"
by J. M. Canfield, R. L. Belford, P. G. Debrunner, and K. Schulten
Chemical Physics, vol.195, no.1-3, pp.59-69, Jun.1, 1995
http://dx.doi.org/10.1016/0301-0104(95)00049-T

(3) "Calculations of Earth-Strength Steady and Oscillating
Magnetic Field Effects in Coenzyme B12 Radical Pair Systems"
by J. M. Canfield, R. L. Belford, and P. G. Debrunner
Molecular Physics, vol.89, no.3, pp.889-930, Oct.20, 1996
http://search.epnet.com/direct.asp?an=7613123&db=aph 

(4) "Approaching Magnetic Field Effects in Biology Using the
Radical Pair Mechanism" by J. M. Canfield, Doctoral Thesis
Department of Physics, University of Illinois at Urbana-Champaign, 1997
UMI (Dissertation Abstracts) control # AAT9812544 (vol.59, no.9, 1999)
call 1-800-521-3042 from US or 1-800-343-5299 from Canada or see
http://www.umi.com/hp/Support/DServices/order/ to order 
also available at many university libraries (OCLC/WorldCat lists some)

TO OBTAIN A COPY OF DSNANI:

Please contact Jeff Canfield by e-mail: 
canfield@engineering.uiuc.edu or canfield@physics.emory.edu
or see his home page at: 
http://ierc.med.uiuc.edu/canfield.html or
http://www.biosci.ohio-state.edu/~jcanfld/

7/2/97 Jeff Canfield

/**********************************************************/
/* Copyright 1997 Jeffrey M. Canfield, Physics Department */
/*   The Board of Trustees of the University of Illinois  */
/*       University of Illinois at Urbana-Champaign       */
/*                   All Rights Reserved                  */
/**********************************************************/