In the block of charge descriptors , the maximum negative charge and the total negative charge are now reported with the minus sign and no longer with the absolute value.

In fact, according to the TPSA method a ring is aromatic if it doesn't include any sp3 carbon.

A list of vertex degrees of a graph can be computed in the Wolfram Language using VertexDegree [ g ], and precomputed vertex degrees are available for particular embeddings of many named graphs via GraphData [ graph , "VertexDegrees" ].

These molecules, characterized by one or more value of 4 in the charge field, are rejected by Dragon. While previously it counted all the edges in the molecule with conventional bond order equal to 1.

Moreover, charge descriptor calculation has been also extended to MDL molecule files, where atomic formal charges can be specified. If the field -d is not specified in the script, all the structures are supposed to be 3D. Unlimited random practice problems and answers with built-in Step-by-step solutions.

Related 4.

Aromaticity detection is performed by an internal algorithm and thus it is independent of the aromatic bonds specified by the user. Specifically, the PRX variable has been given a new interpretation on the basis of the rules and examples given in the original papers of Moriguchi; the RNG variable is now calculated by considering as aromatic any ring without sp3-hybridized carbon atoms; the AMP variable now takes value of 1 also for any hydrocarbon chain connecting -COOH and -NH2 groups.

Implementing Discrete Mathematics: The Moriguchi logP algorithm has been greatly improved.

The script file used to run Dragon in background mode has been changed accordingly. The variable type can take value 2, if the entered molecules are 2D structures, or value 3, if the molecules are 3D. Directed graphs have two types of degrees, known as the indegree and the outdegree.

Major effort has been expended in order to obtain a standard internal representation of molecules regardless of the format of the input files.

Post Your Answer Discard By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service , privacy policy and cookie policy , and that your continued use of the website is subject to these policies. Note that to calculate this descriptor, which is based on geometrical distances between atoms, it's necessary to select the geometrical descriptor block along with the functional groups this only holds for Dragon for Windows. Terms of Use. In effect, in this case the geometrical distance between the two atoms is near 0.

The Ghose-Crippen logP and molar refractivity based on a group contribution method have been improved even if some ambiguities still remain in recognition of some atom-types.

The vertex degrees are illustrated above for a random graph.

To derive this it's helpful to think of the mesh as being made of half-edges.