ACD/HNMR Predictor

What's New

Version 4.0 to 4.5

Algorithms

• Expanded DAT file now contains over 800,000 experimental chemical shifts and 180,000 coupling constants;
• Improved algorithm of diastereotopic protons prediction;
• Additional algorithm of training - analysis of substituents*.

Spectrum Window

• New command - Export to JCAMP;
• New option - Show Shifts near Atoms and corresponding button on the toolbar;
• New option for calculation of shifts - you can choose whether to merge OH and NH signals or not.

Database Window

• Improved Search by Chemical Shifts; new option - Minimum Number of Query Shifts to Match - is added;
• LogD is added to the list of properties in the Calculate Properties command.

Version 3.5 to 4.0

In the calculated Spectrum Window of ACD/HNMR, the new features are:

• show or suppress shifts due to exchangeable protons (-NH and -OH groups)
• many changes to the popular Calculation Protocol Window such as:
  • the ability to remove questionable values from the set of collected fragments or modify their chemical shift value,
  • the ability to build patch files (*.pat) to modify the set of contributing structural fragments used in prediction,
  • a new patch file browsing window to view, edit and remove or add values

In the Database Window, the new features are:

• an all-new Database Forms Manager will allow you to quickly and easily design an input dialog box, so that any time an entry is made to the database, certain database values are requested
• specification of multiple databases to include in system training
• to populate the database, there is now a function to calculate absent shifts - or remove them from the database
• report page creation directly from the Database Window
• commands to Import/Export to SDF files
• the set of search conditions has been expanded to include "exists" (as well as "includes" and "between" and "exact")
• two-level passwords can be set, one for Update and one for Browse and Search
• access to browse and modify the patch file from the Database Window
• new options for entering chemical shift, atom number, multiplicity (from standard pop-up menu or with your own text), and line width
• treatment of exchangeable protons as unique entities in the datasebase table
• a Calculate Properties function, so that predictions from other Advanced Chemistry software (e.g., boiling point) can be automatically executed for each database entry
• more information in the the table of chemical shifts: multiplicity and line-width, and whether the value is calculated

Overall, ACD/HNMR is fully integrated with other version 4.0 ACD/Labs software, most notably ACD/SpecManager

Version 3.0 to 3.5

With ACD/HNMR, now you can:

• include 3-D effects in spectral prediction. HNMR allows 3D molecular structure minimization and utilizes Karplus relationships to predict the proton-proton coupling constants;
• predict spectra for stereoisomers. HNMR identifies diastereotopic protons during predictions;
• number atoms easily. HNMR now utilizes manual numbering or automatic numbering of molecules prior to prediction;
• understand where the predictions come from. HNMR's new Calculation Protocol window allows direct examination, as a histogram plot, on a nucleus by nucleus basis, of which structures within the database were used for the predictions. In this way all database structures utilized for the prediction of a single molecule can be screened one nuclear center at a time;
• search according to user-defined field. HNMR now allows specific fields in the user database to be defined for searching. In this way, appropriate sample or structure specific information can be defined for future searching (notebook number, project name, chemical name, operator, etc.);
• search in multiple databases at a time;
• benefit from enhancements in the prediction algorithm, the self-training system, calculation of confidence limits in self-training, and improvements in networking capabilities under NT 4;
• calculate magnetically non-equivalent spin systems;
• integrate the predicted and literature data with experimental database, i.e., chemical shifts and ranges can be transferred from ACD/SpecManager directly into user databases; and
• integrate HNMR spectral predictions with 32-bit versions of ISIS/Base and ISIS/Draw.

Although HNMR has no user-viewable internal Database (DB), it includes a DAT file to help it make its predictions. The latest version contains a corrected and expanded DAT file with over 800,000 experimental shifts and 180,000 coupling constants which are used for prediction.