The Mantid framework is a software solution developed for the analysis and visualization of neutron scattering and muon spin measurements. The framework is jointly developed by software engineers and scientists at the ISIS Neutron and Muon Facility a
nd the Oak Ridge National Laboratory. The objectives, functionality and novel design aspects of Mantid are described.
Inelastic neutron scattering was used to determine the spin Hamiltonian for the singlet ground state system of fully deuterated BPCB, (C$_{5}$D$_{12}$N)$_{2}$CuBr$_{4}$. A 2-leg spin-1/2 ladder model, with $J_bot = (1.09 pm 0.01)$ meV and $J_| = (0.2
96 pm 0.005)$ meV, accurately describes the data. The experimental limit on the effective inter-ladder exchange constant is $|J_{rm int}^{rm eff}|lesssim 0.006$ meV, and the limit on total diagonal, intra-ladder exchange is $|J_F+J_{F}|leq 0.1$ meV. Including the effects of copper to bromide covalent spin transfer on the magnetic form-factor, the experimental ratios of intra-ladder bond energies are consistent with the predictions of continuous unitary transformation.
