ACD/HNMR Predictor

"ACD/Labs' ¹³C and ¹H NMR prediction software incorporates powerful features that generally result in remarkably accurate calculated NMR spectra."

"The interface is intuitive, and the basic features are all obvious."

"We found no defects or flaws in the software; the program was quick and ran flawlessly under Windows XP Pro with multiple user accounts and simple file sharing disabled. Customer support was outstanding."

"Students less experienced in NMR-based elucidation of structures found the software a useful resource in the sometimes frustrating task of interpreting spectra and confirming structural assignments."

"The software is an extraordinarily practical and convenient compendium of NMR data that effectively replaces the time consuming tasks of looking up individual NMR data from the Web, the primary literature, paper-based libraries of NMR spectra, or similar resources."

--Brian Pagenkopf, J. Am. Chem. Soc., 2005, 127, 3232

Two reviewers of ACD/HNMR 1.0, which is the "grandparent" to ACD/HNMR 10.0 have had favorable things to say about our HNMR spectral prediction software. Here are some excerpts:

"Installation was straightforward and I encountered no problems or difficulties. The user interface is extremely well-designed, intuitive and easy to use. After working with the software for an hour, I was comfortable with most of the features....

"The ¹H NMR program calculates chemical shifts, coupling constants, splitting patterns (1^st and 2^nd order interactions), and peak intensities. Calculations are performed by matching fragments of the chemical structure to a large NMR database. On a 100 MHz Pentium the ... ¹H spectrum for testosterone, with 16 protons and 29 coupling constants, took 70 seconds to calculate....

"The spectrum display routine also sets the magnetic field strength and the spectral linewidth. In the ¹H NMR program, a larger linewidth is specified for  - OH and  - NH protons. ... The ¹H program simulates selective homonuclear decoupling. These simulations are useful for designing experiments, interpreting unknowns, and teaching NMR.

"Because the ¹H NMR prediction includes splitting patterns and because proton chemical shifts are not as easy to predict, the HNMR program is more complex. I used the HNMR program to calculate predicted proton spectra for 15 compounds for which I already had experimental data. The standard deviation between the predicted and observed chemical shifts was +/- 0.24 ppm. The maximum error for this data set was 0.96 ppm for the hydroxyl proton in 1,3-propandiol. This error is, however, within the +/- 1.33 ppm confidence interval reported by the program.

"... I also examined the predicted proton NMR spectrum of crotonaldehyde (CH3CH=CHCHO) to test the programs' ability to handle complex splitting patterns. The predicted spectrum very closely matched the coupling constants, splitting patterns, and relative intensities of the experimental data. The standards deviation of the error between the predicted coupling constants and the five observable coupling constants was only +/- 0.4 Hz."

-- Scott van Bramer, Concepts in Magnetic Resonance, 9(4) 271-273 (1997).

"Each section of the total package is accompanied by a detailed users' manual. These are among the best written manuals I have seen and might well serve as models for others who write about complex computer software programs. However, much of the program is sufficiently user friendly that one may intuit the operation with considerable success. ...

"... for proton spectra, ... one must not only project chemical shifts but coupling constants as well. Again working with the huge database and molecular fragments, the ACD/HNMR program does surprisingly well."

-- William B. Smith, The NMR Newsletter, 1997, No. 455, Page 25