The authors regret that errors were made in the derivation of eq 3C, which also affect the final form of eq 6C but not that of eq 4. These errors do not change the conclusions of the paper, because the corrected eq 6C still expresses a multitorsional potential that is a product of cosines of virtual-bond dihedrals along a folded chain segment except that there are sines and not cosines of the first and the last dihedral, respectively, while cosines only appeared in the incorrect equation. Thus, the corrected expression still corresponds to directing the chain before and after a folded (in most cases a helical) chain segment.
The corrected eqs 3C and 6C are below. To keep correspondence with the original paper, they are labeled 3C and 6C, respectively. The revised derivation of both equations is provided in the Supporting Information.
![]() |
3C |
![]() |
6C |
where
![]() |
In eqs 3C and 6C, m is the number of Cα atoms in the segment
(the length of the segment), k is the index of the
first residue of the segment, θi is the planar angle between
,
, and
, and γi is the dihedral angle defined by atoms
,
,
, and
. The angles Φi and
are phase angles and the coefficients Ci depend on the kind of respective
amino-acid residues and the neighboring residues.
Following
the correction, eq 18C, which expresses the multitorsional energy term corresponding
to a folded chain segment,
, which we recommend to introduce to coarse-grained
force fields, is replaced by eq 18C.
![]() |
18C |
where M is the multiplicity of the respective term and the coefficients bi,M are parameters.
Acknowledgments
This work was supported by grant UMO-2021/40/Q/ST4/00035 from the National Science Centre of Poland (Narodowe Centrum Nauki) (to A.L.) and by the Marsden Fund Council from Government funding, administered by the Royal Society of New Zealand (grant number MFP-21-UOA-069) (to C.S.). Computational resources were provided by (a) the Centre of Informatics – Tricity Academic Supercomputer & Network (CI TASK) in Gdańsk (b) the Interdisciplinary Center of Mathematical and Computer Modeling (ICM) the University of Warsaw under grants No. GA71-23, (c) the Academic Computer Centre Cyfronet AGH in Krakow under grants unres19 and unres2021, and (d) our 796-processor Beowulf cluster at the Faculty of Chemistry, University of Gdańsk.
Supporting Information Available
The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.jpcb.2c08574.
Supplementary Material
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.




