Common words:
* Action
* Addition
* Attention
* Condition
* Creation
* Definition
* Education
* Explanation
* Formation
* Information
* Invitation
* Location
* Nation
* Operation
* Population
* Preparation
* Production
* Reaction
* Relation
* Situation
* Solution
* Station
* Tradition
Less common words:
* Ablation
* Accretion
* Allocation
* Alteration
* Amputation
* Annunciation
* Apparition
* Articulation
* Assassination
* Aviation
* Combustion
* Concatenation
* Conflagration
* Conjunction
* Consolation
* Constitution
* Contraction
* Conversation
* Correlation
* Declamation
* Deflation
* Delegation
* Demolition
* Denunciation
* Derivation
* Deviation
* Digestion
* Distillation
* Distribution
* Elucidation
* Emancipation
* Excitation
* Exhortation
* Fabrication
* Frustration
* Graduation
* Illumination
* Implication
* Incarnation
* Incubation
* Inflation
* Innovation
* Instillation
* Integration
* Interpretation
* Iteration
* Justification
* Legislation
* Liberation
* Limitation
* Litigation
* Locomotion
* Magnification
* Manipulation
* Medication
* Meditation
* Modification
* Multiplication
* Navigation
* Negotiation
* Nomination
* Notation
* Observation
* Oscillation
* Oxidation
* Participation
* Penetration
* Perpetuation
* Perspiration
* Plantation
* Polarization
* Precipitation
* Predication
* Presentation
* Preservation
* Probation
* Proclamation
* Propagation
* Proportion
* Revelation
* Revolution
* Saturation
* Secretion
* Selection
* Separation
* Simplification
* Simulation
* Specialization
* Specification
* Stimulation
* Sublimation
* Substitution
* Subtraction
* Supervision
* Transformation
* Transmission
* Translation
* Transportation
* Vaccination
* Variation
* Verification
* Violation
* Visitation
* Vocation
This is just a small sample. There are many more words ending in "-tion"!