ECCE 9.0.1

ECCE 9.0.1, a bug-fix release of the 9 series. It was released without a manual test round; the regression set (tests/teaching) passed on Debian with direct and Slurm job submission. Please report problems as issues.

Platforms. Linux (Debian 13; Ubuntu 24.04, RHEL/Rocky 9 and Fedora packages are built on those systems but not tested). Windows 10 and 11. macOS, Apple silicon and Intel: experimental.

Geometry constraints and dummy atoms (#306, #309)

• Constraints are defined in the Builder, under Tools › Geometry Constraints… or from a right-click on selected atoms, at any run type. They are saved with the calculation. The Calculation Editor shows how many are defined and that only geometry optimisations use them; Verify says the same.
• Atom order is checked: the centre of an angle is the atom bonded to both others, and a torsion must be a bonded chain. Picks in the wrong order are reordered and shown (for example "Angle H2–N1–H3 (centre N1)"); atoms that are not bonded as required are added only after confirmation.
• NWChem: a fixed atom made NWChem ignore bond, angle and torsion constraints without a message. NWChem cannot combine the two; the input now makes NWChem stop with an error instead, and Verify reports the combination.
• Dummy atoms (X) attach at an open site like any atom (for NH3, on the C3 axis, 1.01 Å from N). For a saturated centre, Tools › Add Dummy Atom… places X at the centre of the selected atoms, or on the axis through the first picked atom at a given distance (methane: pick C, then three H). Codes that cannot use dummy atoms (Quantum ESPRESSO, GROMACS) refuse them with a message.
• ECCE-QM optimises with dummy atoms and geometry constraints. Constrained optimisations agree with NWChem to 2.5e-8 Eh and with ORCA to 3e-9 Eh.
• Help: a new page, Constraints and dummy atoms.

NWChem (#297)

• MP2 and coupled-cluster inputs generate again. Open-shell CC runs through TCE, and TCE energies are read.

Organizer and login

• Forgot password… in the login window, on this computer's own data server (#203). On a central server, the window names the command an administrator runs (ecce-dataserver-adduser --passwd NAME).
• Example calculations are imported into an "Examples" project at a user's first start (#302). An existing Examples project is not touched, and one that is deleted does not come back. File › Open Example Calculations still makes a fresh copy.
• Imported calculations: ORCA jobs with only a functional (! B3LYP) show DFT as their theory; NWChem jobs that optimise and then compute frequencies show GeoVib.
• MOPAC progress (#303): FORCE runs show the point reached, and the SCF is marked converged.
• Windows: selecting calculations redraws the menu bar only when a menu changes (#296; not yet checked on Windows).

Builder and Calculation Editor

• Ctrl+click adds to the selection, as Shift+click does.
• Ctrl+X, Ctrl+C, Ctrl+V and Ctrl+Z work in the 3-D view; in a text field they edit the text.
• The element selector opens below its button and has a periodic-table icon (#304).
• No black areas in the Calculation Editor while the Code Change question is open (#308).
• Verify knows the new charge, NBO and dummy-atom keywords for Gaussian 16, MOPAC and ORCA.

Known issues

• Undo of an edit that re-creates atoms drops the constraints on those atoms without a message.
• GROMACS (experimental) does not yet handle periodic molecules such as clay sheets (#262) or force-field folders (#260).
• The Build pane cannot be made taller than the other panes in its column allow (#293).
• The MO diagram is experimental; it can be incomplete for larger molecules.

Packages

System	Files
Debian 13	ecce-client_9.0.1_amd64.deb, ecce-server_9.0.1_amd64.deb
Ubuntu 24.04	ecce-client_9.0.1_ubuntu24.04_amd64.deb, ecce-server_9.0.1_ubuntu24.04_amd64.deb
RHEL/Rocky 9	ecce-client-9.0.1-1.el9.x86_64.rpm, ecce-server-9.0.1-1.el9.x86_64.rpm
Fedora	ecce-client-9.0.1-1.fedora.x86_64.rpm, ecce-server-9.0.1-1.fedora.x86_64.rpm
macOS 11 or newer (experimental)	ECCE-9.0.1-arm64.dmg (Apple silicon), ECCE-9.0.1-x86_64.dmg (Intel)
Windows 10/11	ECCE-windows-9.0.1.msi (installer) or ECCE-windows-9.0.1.zip

Installation: Installing ECCE. Videos: Your first calculation with ECCE-QM, Your first ORCA calculation with ECCE.