Second_Order_Spectra - Simulation of Second Order Spectra...

Info icon This preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Simulation of Second Order Spectra Using SPINEVOLUTION Spring, 2010 Introduction Although we frequently assume that scalar couplings are small compared to the differences in resonance positions due to chemical shifts and analyze spectra in terms of idealized (first order) multiplet structures, this assumption is often violated. It is therefore useful to understand the effects that violation can have on spectra (second order effects). It is also useful to have tools that allow one to extract chemical shifts and coupling constants from spectra in which they cannot be measured directly from positions of multiplet peaks. There are many tools for doing this, including tools based on density matrix calculations (GAMMA, for example, S.A. Smith et. al, J. Magn. Reson.106A, 75- 105 (1994)). This particular approach has the advantage of being able to simultaneously simulate the effects of complex pulse sequences, evolution under various Hamiltonians, and spin relaxation. The program SPINEVOLUTION, which we will use in this exercise, falls in this general class of tools. SPINEVOLUTION was written by M.Veshtort and R.G.Griffin primarily with the intent of simulating a whole variety of complex NMR experiments, including solids NMR experiments, something in which the Griffin lab specializes. However, it will simulate simple second order 1D experiments and we will use this capability to illustrate some of the principles discussed in class. The published article describing the software is: J. Magn. Reson., 178 (2006) 248-282. There is a support website with examples and other information at: http://web.mit.edu/fbml/cmr/griffin-group/SPINEVOLUTION/index.htm Downloads for a variety of platforms are available at: http://web.mit.edu/fbml/cmr/griffin-group/SPINEVOLUTION/Download.htm SPINEVOLUTION is implemented through the command “spinev” followed by the name of a script containing a series of definitions and commands. The program would normally begin with an equilibrium density matrix, transform it according to a given pulse sequence, and extract observables from density matrices at various points of time in an observation domain. For X and Y magnetization this is presented as a list of real and imaginary pairs of numbers – essentially an FID.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern