Features Overview

ACoord provides a comprehensive set of tools for visualizing and editing atomic structures.

Core Features

3D Visualization

Interactive 3D rendering powered by Three.js:

• Real-time rotation, pan, and zoom
• High-quality atom and bond rendering
• Adjustable lighting
• Smooth animations

Atom Selection

Selection tools:

• Click to select single atoms
• Ctrl/Cmd+click for multi-select
• Box selection for regions
• Selection persistence across frames

Bond Measurement

Bond analysis tools:

• Automatic bond detection
• Distance measurement
• Bond creation and deletion

Unit Cell Editor

Crystal structure editing:

• Lattice parameter modification
• Unit cell visualization
• Supercell generation

Color Schemes

Customizable atom colors:

• Built-in presets (Bright, Jmol)
• Custom color scheme creation
• Import/export configurations

Fixed Atoms

Constraint management for geometry optimization:

• Mark atoms as fixed (constrained) or free
• Visual indicator: white 3D cross marker on atom surface
• Syncs with format-native constraints in POSCAR, QE, STRU, OpenMX, CASTEP cell, and native .acoord files where supported
• Omits redundant constraint flags when all atoms are unconstrained

Additional Features

Trajectory Support

• Multi-frame file visualization
• Animation playback controls
• Frame-by-frame navigation

File Format Support

15+ formats supported:

Category	Formats
Crystal	CIF, POSCAR, CONTCAR
Molecule	XYZ, PDB
Trajectory	XDATCAR, OUTCAR
Quantum	Gaussian, ORCA, QE, ABACUS, CASTEP, SIESTA, OpenMX
Native	.acoord

Undo/Redo

• Up to 100 history steps
• All edit operations supported

Getting Started

1. Installation — Install ACoord
2. Getting Started — Open your first structure
3. Viewing Tutorial — Learn navigation
4. Editing Tutorial — Learn editing

Keyboard Shortcuts

Category	Shortcut	Action
Navigation	Left-drag	Rotate
	Right-drag	Pan
	Scroll	Zoom
Selection	Click	Select atom
	Ctrl/Cmd+click	Multi-select
	Ctrl+A	Select all
	Ctrl+I	Invert selection
	Esc	Deselect all
Editing	A	Enter add atom mode
	D	Delete mode
	V	Select mode
	Delete/Backspace	Delete selected
	Ctrl+Z	Undo
	Ctrl+Y	Redo
	Ctrl+S	Save
	Ctrl+C	Copy selected atoms
	Ctrl+V	Paste atoms

Need More Help?

• Check individual feature pages for details
• Read tutorials for step-by-step guides
• Report issues on GitHub