Common words:
* Action
* Addiction
* Affection
* Attention
* Conclusion
* Connection
* Construction
* Correction
* Creation
* Decision
* Definition
* Description
* Direction
* Education
* Election
* Fiction
* Function
* Information
* Inspection
* Instruction
* Interaction
* Location
* Nation
* Option
* Prediction
* Production
* Protection
* Reaction
* Reflection
* Relation
* Selection
* Solution
* Tradition
Less common words:
* Abduction
* Admonition
* Ascension
* Coalition
* Collusion
* Concession
* Confession
* Conjunction
* Conscription
* Declination
* Delegation
* Denunciation
* Derivation
* Desolation
* Detention
* Diminution
* Discretion
* Distraction
* Eruption
* Erosion
* Expansion
* Extinction
* Fraction
* Friction
* Inception
* Inflection
* Injection
* Junction
* Objection
* Omission
* Oppression
* Perdition
* Precision
* Prohibition
* Recollection
* Reconciliation
* Reduction
* Repetition
* Resurrection
* Subjection
* Succession
* Suspension
* Transcendence
* Translation
* Transmission
This list is not exhaustive, but it provides a good starting point. There are many other words ending in "-cion" depending on the specific field or context.