Magnetic calculus and semiclassical trace formulas

The aim of this paper is to show how the magnetic calculus developed in Mantoiu and Purice (2004 J. Math. Phys. 45 1394-417), Iftimie et al (2007 Publ. RIMS 43 585-624), Iftimie et al (Commun. Partial Differ. Equ. to appear), Mantoiu et al (2007 J. Funct. Anal. 250 42-67) and Lein et al (arXiv:0901.3704) permits us to give new information on the nature of the coefficients of the expansion of the trace of a function of the magnetic Schrodinger operator whose existence was established in (Helffer and Robert 1990 Asymptotic Anal. 3 91-103).